[format.python] initial formatting of the python code

This patch was generated by black [1]::

    make format.python

[1] https://github.com/psf/black

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

184 files changed, 2808 insertions, 2844 deletions

diff --git a/searx/__init__.py b/searx/__init__.py
index b1626ae9f..d2d389ea9 100644
--- a/searx/__init__.py
+++ b/searx/__init__.py
@@ -29,6 +29,7 @@ if settings is not None:
 
 _unset = object()
 
+
 def get_setting(name, default=_unset):
     """Returns the value to which ``name`` point.  If there is no such name in the
     settings and the ``default`` is unset, a :py:obj:`KeyError` is raised.
@@ -80,14 +81,9 @@ def logging_config_debug():
             'levelname': {'color': 8},
             'name': {'color': 8},
             'programname': {'color': 'cyan'},
-            'username': {'color': 'yellow'}
+            'username': {'color': 'yellow'},
         }
-        coloredlogs.install(
-            level=log_level,
-            level_styles=level_styles,
-            field_styles=field_styles,
-            fmt=LOG_FORMAT_DEBUG
-        )
+        coloredlogs.install(level=log_level, level_styles=level_styles, field_styles=field_styles, fmt=LOG_FORMAT_DEBUG)
     else:
         logging.basicConfig(level=logging.getLevelName(log_level), format=LOG_FORMAT_DEBUG)
 
diff --git a/searx/answerers/random/answerer.py b/searx/answerers/random/answerer.py
index d5223e517..e6c383330 100644
--- a/searx/answerers/random/answerer.py
+++ b/searx/answerers/random/answerer.py
@@ -8,13 +8,12 @@ from flask_babel import gettext
 # specifies which search query keywords triggers this answerer
 keywords = ('random',)
 
-random_int_max = 2**31
+random_int_max = 2 ** 31
 random_string_letters = string.ascii_lowercase + string.digits + string.ascii_uppercase
 
 
 def random_characters():
-    return [random.choice(random_string_letters)
-            for _ in range(random.randint(8, 32))]
+    return [random.choice(random_string_letters) for _ in range(random.randint(8, 32))]
 
 
 def random_string():
@@ -39,11 +38,13 @@ def random_uuid():
     return str(uuid.uuid4())
 
 
-random_types = {'string': random_string,
-                'int': random_int,
-                'float': random_float,
-                'sha256': random_sha256,
-                'uuid': random_uuid}
+random_types = {
+    'string': random_string,
+    'int': random_int,
+    'float': random_float,
+    'sha256': random_sha256,
+    'uuid': random_uuid,
+}
 
 
 # required answerer function
@@ -62,6 +63,8 @@ def answer(query):
 # required answerer function
 # returns information about the answerer
 def self_info():
-    return {'name': gettext('Random value generator'),
-            'description': gettext('Generate different random values'),
-            'examples': ['random {}'.format(x) for x in random_types]}
+    return {
+        'name': gettext('Random value generator'),
+        'description': gettext('Generate different random values'),
+        'examples': ['random {}'.format(x) for x in random_types],
+    }
diff --git a/searx/answerers/statistics/answerer.py b/searx/answerers/statistics/answerer.py
index abd4be7f5..60f0d304f 100644
--- a/searx/answerers/statistics/answerer.py
+++ b/searx/answerers/statistics/answerer.py
@@ -4,11 +4,7 @@ from operator import mul
 from flask_babel import gettext
 
 
-keywords = ('min',
-            'max',
-            'avg',
-            'sum',
-            'prod')
+keywords = ('min', 'max', 'avg', 'sum', 'prod')
 
 
 # required answerer function
@@ -47,6 +43,8 @@ def answer(query):
 # required answerer function
 # returns information about the answerer
 def self_info():
-    return {'name': gettext('Statistics functions'),
-            'description': gettext('Compute {functions} of the arguments').format(functions='/'.join(keywords)),
-            'examples': ['avg 123 548 2.04 24.2']}
+    return {
+        'name': gettext('Statistics functions'),
+        'description': gettext('Compute {functions} of the arguments').format(functions='/'.join(keywords)),
+        'examples': ['avg 123 548 2.04 24.2'],
+    }
diff --git a/searx/autocomplete.py b/searx/autocomplete.py
index a55377cd9..b8d272c32 100644
--- a/searx/autocomplete.py
+++ b/searx/autocomplete.py
@@ -120,14 +120,15 @@ def wikipedia(query, lang):
     return []
 
 
-backends = {'dbpedia': dbpedia,
-            'duckduckgo': duckduckgo,
-            'google': google,
-            'startpage': startpage,
-            'swisscows': swisscows,
-            'qwant': qwant,
-            'wikipedia': wikipedia
-            }
+backends = {
+    'dbpedia': dbpedia,
+    'duckduckgo': duckduckgo,
+    'google': google,
+    'startpage': startpage,
+    'swisscows': swisscows,
+    'qwant': qwant,
+    'wikipedia': wikipedia,
+}
 
 
 def search_autocomplete(backend_name, query, lang):
diff --git a/searx/data/__init__.py b/searx/data/__init__.py
index 5937ea557..87bfb5477 100644
--- a/searx/data/__init__.py
+++ b/searx/data/__init__.py
@@ -23,10 +23,12 @@ from pathlib import Path
 
 data_dir = Path(__file__).parent
 
+
 def _load(filename):
     with open(data_dir / filename, encoding='utf-8') as f:
         return json.load(f)
 
+
 def ahmia_blacklist_loader():
     """Load data from `ahmia_blacklist.txt` and return a list of MD5 values of onion
     names.  The MD5 values are fetched by::
@@ -39,6 +41,7 @@ def ahmia_blacklist_loader():
     with open(str(data_dir / 'ahmia_blacklist.txt'), encoding='utf-8') as f:
         return f.read().split()
 
+
 ENGINES_LANGUAGES = _load('engines_languages.json')
 CURRENCIES = _load('currencies.json')
 USER_AGENTS = _load('useragents.json')
diff --git a/searx/engines/1337x.py b/searx/engines/1337x.py
index e6a243596..730a4c445 100644
--- a/searx/engines/1337x.py
+++ b/searx/engines/1337x.py
@@ -43,11 +43,15 @@ def response(resp):
         filesize, filesize_multiplier = filesize_info.split()
         filesize = get_torrent_size(filesize, filesize_multiplier)
 
-        results.append({'url': href,
-                        'title': title,
-                        'seed': seed,
-                        'leech': leech,
-                        'filesize': filesize,
-                        'template': 'torrent.html'})
+        results.append(
+            {
+                'url': href,
+                'title': title,
+                'seed': seed,
+                'leech': leech,
+                'filesize': filesize,
+                'template': 'torrent.html',
+            }
+        )
 
     return results
diff --git a/searx/engines/__init__.py b/searx/engines/__init__.py
index 44ea9a4bd..fa9749e9d 100644
--- a/searx/engines/__init__.py
+++ b/searx/engines/__init__.py
@@ -57,6 +57,7 @@ engine_shortcuts = {}
 
 """
 
+
 def load_engine(engine_data):
     """Load engine from ``engine_data``.
 
@@ -166,20 +167,19 @@ def set_language_attributes(engine):
         # settings.yml
         if engine.language not in engine.supported_languages:
             raise ValueError(
-                "settings.yml - engine: '%s' / language: '%s' not supported" % (
-                    engine.name, engine.language ))
+                "settings.yml - engine: '%s' / language: '%s' not supported" % (engine.name, engine.language)
+            )
 
         if isinstance(engine.supported_languages, dict):
-            engine.supported_languages = {
-                engine.language : engine.supported_languages[engine.language]
-            }
+            engine.supported_languages = {engine.language: engine.supported_languages[engine.language]}
         else:
             engine.supported_languages = [engine.language]
 
     # find custom aliases for non standard language codes
     for engine_lang in engine.supported_languages:
         iso_lang = match_language(engine_lang, BABEL_LANGS, fallback=None)
-        if (iso_lang
+        if (
+            iso_lang
             and iso_lang != engine_lang
             and not engine_lang.startswith(iso_lang)
             and iso_lang not in engine.supported_languages
@@ -197,14 +197,12 @@ def set_language_attributes(engine):
         }
         engine.fetch_supported_languages = (
             # pylint: disable=protected-access
-            lambda: engine._fetch_supported_languages(
-                get(engine.supported_languages_url, headers=headers))
+            lambda: engine._fetch_supported_languages(get(engine.supported_languages_url, headers=headers))
         )
 
 
 def update_attributes_for_tor(engine):
-    if (settings['outgoing'].get('using_tor_proxy')
-        and hasattr(engine, 'onion_url') ):
+    if settings['outgoing'].get('using_tor_proxy') and hasattr(engine, 'onion_url'):
         engine.search_url = engine.onion_url + getattr(engine, 'search_path', '')
         engine.timeout += settings['outgoing'].get('extra_proxy_timeout', 0)
 
@@ -217,9 +215,7 @@ def is_missing_required_attributes(engine):
     missing = False
     for engine_attr in dir(engine):
         if not engine_attr.startswith('_') and getattr(engine, engine_attr) is None:
-            logger.error(
-                'Missing engine config attribute: "{0}.{1}"'
-                .format(engine.name, engine_attr))
+            logger.error('Missing engine config attribute: "{0}.{1}"'.format(engine.name, engine_attr))
             missing = True
     return missing
 
@@ -230,8 +226,7 @@ def is_engine_active(engine):
         return False
 
     # exclude onion engines if not using tor
-    if ('onions' in engine.categories
-        and not settings['outgoing'].get('using_tor_proxy') ):
+    if 'onions' in engine.categories and not settings['outgoing'].get('using_tor_proxy'):
         return False
 
     return True
@@ -253,8 +248,7 @@ def register_engine(engine):
 
 
 def load_engines(engine_list):
-    """usage: ``engine_list = settings['engines']``
-    """
+    """usage: ``engine_list = settings['engines']``"""
     engines.clear()
     engine_shortcuts.clear()
     categories.clear()
diff --git a/searx/engines/ahmia.py b/searx/engines/ahmia.py
index b9a0086bd..33e0cc393 100644
--- a/searx/engines/ahmia.py
+++ b/searx/engines/ahmia.py
@@ -25,9 +25,7 @@ page_size = 10
 # search url
 search_url = 'http://juhanurmihxlp77nkq76byazcldy2hlmovfu2epvl5ankdibsot4csyd.onion/search/?{query}'
 time_range_support = True
-time_range_dict = {'day': 1,
-                   'week': 7,
-                   'month': 30}
+time_range_dict = {'day': 1, 'week': 7, 'month': 30}
 
 # xpaths
 results_xpath = '//li[@class="result"]'
@@ -54,7 +52,7 @@ def response(resp):
     # trim results so there's not way too many at once
     first_result_index = page_size * (resp.search_params.get('pageno', 1) - 1)
     all_results = eval_xpath_list(dom, results_xpath)
-    trimmed_results = all_results[first_result_index:first_result_index + page_size]
+    trimmed_results = all_results[first_result_index : first_result_index + page_size]
 
     # get results
     for result in trimmed_results:
@@ -65,10 +63,7 @@ def response(resp):
         title = extract_text(eval_xpath(result, title_xpath))
         content = extract_text(eval_xpath(result, content_xpath))
 
-        results.append({'url': cleaned_url,
-                        'title': title,
-                        'content': content,
-                        'is_onion': True})
+        results.append({'url': cleaned_url, 'title': title, 'content': content, 'is_onion': True})
 
     # get spelling corrections
     for correction in eval_xpath_list(dom, correction_xpath):
diff --git a/searx/engines/apkmirror.py b/searx/engines/apkmirror.py
index 746a8cd9c..da84bc79e 100644
--- a/searx/engines/apkmirror.py
+++ b/searx/engines/apkmirror.py
@@ -35,8 +35,8 @@ search_url = base_url + '/?post_type=app_release&searchtype=apk&page={pageno}&{q
 
 def request(query, params):
     params['url'] = search_url.format(
-        pageno = params['pageno'],
-        query = urlencode({'s': query}),
+        pageno=params['pageno'],
+        query=urlencode({'s': query}),
     )
     logger.debug("query_url --> %s", params['url'])
     return params
@@ -55,11 +55,7 @@ def response(resp):
         url = base_url + link.attrib.get('href') + '#downloads'
         title = extract_text(link)
         img_src = base_url + eval_xpath_getindex(result, './/img/@src', 0)
-        res = {
-            'url': url,
-            'title': title,
-            'img_src': img_src
-        }
+        res = {'url': url, 'title': title, 'img_src': img_src}
 
         results.append(res)
 
diff --git a/searx/engines/archlinux.py b/searx/engines/archlinux.py
index 1aa8d0ade..1cfb3983f 100644
--- a/searx/engines/archlinux.py
+++ b/searx/engines/archlinux.py
@@ -97,7 +97,7 @@ main_langs = {
     'sl': 'Slovenský',
     'th': 'ไทย',
     'uk': 'Українська',
-    'zh': '简体中文'
+    'zh': '简体中文',
 }
 supported_languages = dict(lang_urls, **main_langs)
 
@@ -141,7 +141,6 @@ def response(resp):
         href = urljoin(base_url, link.attrib.get('href'))
         title = extract_text(link)
 
-        results.append({'url': href,
-                        'title': title})
+        results.append({'url': href, 'title': title})
 
     return results
diff --git a/searx/engines/artic.py b/searx/engines/artic.py
index 104ab8839..c0ae0a5e7 100644
--- a/searx/engines/artic.py
+++ b/searx/engines/artic.py
@@ -27,19 +27,23 @@ nb_per_page = 20
 search_api = 'https://api.artic.edu/api/v1/artworks/search?'
 image_api = 'https://www.artic.edu/iiif/2/'
 
+
 def request(query, params):
 
-    args = urlencode({
-        'q' : query,
-        'page' : params['pageno'],
-        'fields' : 'id,title,artist_display,medium_display,image_id,date_display,dimensions,artist_titles',
-        'limit' : nb_per_page,
-        })
+    args = urlencode(
+        {
+            'q': query,
+            'page': params['pageno'],
+            'fields': 'id,title,artist_display,medium_display,image_id,date_display,dimensions,artist_titles',
+            'limit': nb_per_page,
+        }
+    )
     params['url'] = search_api + args
 
     logger.debug("query_url --> %s", params['url'])
     return params
 
+
 def response(resp):
 
     results = []
@@ -50,14 +54,16 @@ def response(resp):
         if not result['image_id']:
             continue
 
-        results.append({
-            'url': 'https://artic.edu/artworks/%(id)s' % result,
-            'title': result['title'] + " (%(date_display)s) //  %(artist_display)s" % result,
-            'content': result['medium_display'],
-            'author': ', '.join(result['artist_titles']),
-            'img_src': image_api + '/%(image_id)s/full/843,/0/default.jpg' % result,
-            'img_format': result['dimensions'],
-            'template': 'images.html'
-        })
+        results.append(
+            {
+                'url': 'https://artic.edu/artworks/%(id)s' % result,
+                'title': result['title'] + " (%(date_display)s) //  %(artist_display)s" % result,
+                'content': result['medium_display'],
+                'author': ', '.join(result['artist_titles']),
+                'img_src': image_api + '/%(image_id)s/full/843,/0/default.jpg' % result,
+                'img_format': result['dimensions'],
+                'template': 'images.html',
+            }
+        )
 
     return results
diff --git a/searx/engines/arxiv.py b/searx/engines/arxiv.py
index 09ea07ea5..a1a58172d 100644
--- a/searx/engines/arxiv.py
+++ b/searx/engines/arxiv.py
@@ -20,8 +20,9 @@ about = {
 categories = ['science']
 paging = True
 
-base_url = 'https://export.arxiv.org/api/query?search_query=all:'\
-           + '{query}&start={offset}&max_results={number_of_results}'
+base_url = (
+    'https://export.arxiv.org/api/query?search_query=all:' + '{query}&start={offset}&max_results={number_of_results}'
+)
 
 # engine dependent config
 number_of_results = 10
@@ -31,9 +32,7 @@ def request(query, params):
     # basic search
     offset = (params['pageno'] - 1) * number_of_results
 
-    string_args = dict(query=query,
-                       offset=offset,
-                       number_of_results=number_of_results)
+    string_args = dict(query=query, offset=offset, number_of_results=number_of_results)
 
     params['url'] = base_url.format(**string_args)
 
@@ -65,10 +64,7 @@ def response(resp):
 
         publishedDate = datetime.strptime(eval_xpath_getindex(entry, './/published', 0).text, '%Y-%m-%dT%H:%M:%SZ')
 
-        res_dict = {'url': url,
-                    'title': title,
-                    'publishedDate': publishedDate,
-                    'content': content}
+        res_dict = {'url': url, 'title': title, 'publishedDate': publishedDate, 'content': content}
 
         results.append(res_dict)
 
diff --git a/searx/engines/bandcamp.py b/searx/engines/bandcamp.py
index 62745243f..ba951a393 100644
--- a/searx/engines/bandcamp.py
+++ b/searx/engines/bandcamp.py
@@ -44,9 +44,7 @@ def request(query, params):
       pageno  : 1 # number of the requested page
     '''
 
-    search_path = search_string.format(
-        query=urlencode({'q': query}),
-        page=params['pageno'])
+    search_path = search_string.format(query=urlencode({'q': query}), page=params['pageno'])
 
     params['url'] = base_url + search_path
 
diff --git a/searx/engines/base.py b/searx/engines/base.py
index 463274681..5a2d66619 100755
--- a/searx/engines/base.py
+++ b/searx/engines/base.py
@@ -21,8 +21,10 @@ about = {
 
 categories = ['science']
 
-base_url = 'https://api.base-search.net/cgi-bin/BaseHttpSearchInterface.fcgi'\
-           + '?func=PerformSearch&{query}&boost=oa&hits={hits}&offset={offset}'
+base_url = (
+    'https://api.base-search.net/cgi-bin/BaseHttpSearchInterface.fcgi'
+    + '?func=PerformSearch&{query}&boost=oa&hits={hits}&offset={offset}'
+)
 
 # engine dependent config
 paging = True
@@ -47,7 +49,7 @@ shorcut_dict = {
     'source:': 'dcsource:',
     'subject:': 'dcsubject:',
     'title:': 'dctitle:',
-    'type:': 'dcdctype:'
+    'type:': 'dcdctype:',
 }
 
 
@@ -59,9 +61,7 @@ def request(query, params):
     # basic search
     offset = (params['pageno'] - 1) * number_of_results
 
-    string_args = dict(query=urlencode({'query': query}),
-                       offset=offset,
-                       hits=number_of_results)
+    string_args = dict(query=urlencode({'query': query}), offset=offset, hits=number_of_results)
 
     params['url'] = base_url.format(**string_args)
 
@@ -93,7 +93,7 @@ def response(resp):
                 if len(item.text) > 300:
                     content += "..."
 
-# dates returned by the BASE API are not several formats
+        # dates returned by the BASE API are not several formats
         publishedDate = None
         for date_format in ['%Y-%m-%dT%H:%M:%SZ', '%Y-%m-%d', '%Y-%m', '%Y']:
             try:
@@ -103,14 +103,9 @@ def response(resp):
                 pass
 
         if publishedDate is not None:
-            res_dict = {'url': url,
-                        'title': title,
-                        'publishedDate': publishedDate,
-                        'content': content}
+            res_dict = {'url': url, 'title': title, 'publishedDate': publishedDate, 'content': content}
         else:
-            res_dict = {'url': url,
-                        'title': title,
-                        'content': content}
+            res_dict = {'url': url, 'title': title, 'content': content}
 
         results.append(res_dict)
 
diff --git a/searx/engines/bing.py b/searx/engines/bing.py
index 3917e54c1..59fc22be4 100644
--- a/searx/engines/bing.py
+++ b/searx/engines/bing.py
@@ -36,9 +36,11 @@ inital_query = 'search?{query}&search=&form=QBLH'
 # following queries: https://www.bing.com/search?q=foo&search=&first=11&FORM=PERE
 page_query = 'search?{query}&search=&first={offset}&FORM=PERE'
 
+
 def _get_offset_from_pageno(pageno):
     return (pageno - 1) * 10 + 1
 
+
 def request(query, params):
 
     offset = _get_offset_from_pageno(params.get('pageno', 1))
@@ -53,30 +55,23 @@ def request(query, params):
     if params['language'] == 'all':
         lang = 'EN'
     else:
-        lang = match_language(
-            params['language'], supported_languages, language_aliases
-        )
+        lang = match_language(params['language'], supported_languages, language_aliases)
 
-    query = 'language:{} {}'.format(
-        lang.split('-')[0].upper(), query
-    )
+    query = 'language:{} {}'.format(lang.split('-')[0].upper(), query)
 
-    search_path = search_string.format(
-        query = urlencode({'q': query}),
-        offset = offset)
+    search_path = search_string.format(query=urlencode({'q': query}), offset=offset)
 
     if offset > 1:
-        referer = base_url + inital_query.format(query = urlencode({'q': query}))
+        referer = base_url + inital_query.format(query=urlencode({'q': query}))
         params['headers']['Referer'] = referer
-        logger.debug("headers.Referer --> %s", referer )
+        logger.debug("headers.Referer --> %s", referer)
 
     params['url'] = base_url + search_path
     params['headers']['Accept-Language'] = "en-US,en;q=0.5"
-    params['headers']['Accept'] = (
-        'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'
-    )
+    params['headers']['Accept'] = 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'
     return params
 
+
 def response(resp):
 
     results = []
@@ -87,7 +82,7 @@ def response(resp):
     for result in eval_xpath(dom, '//div[@class="sa_cc"]'):
 
         # IMO //div[@class="sa_cc"] does no longer match
-        logger.debug('found //div[@class="sa_cc"] --> %s',  result)
+        logger.debug('found //div[@class="sa_cc"] --> %s', result)
 
         link = eval_xpath(result, './/h3/a')[0]
         url = link.attrib.get('href')
@@ -95,11 +90,7 @@ def response(resp):
         content = extract_text(eval_xpath(result, './/p'))
 
         # append result
-        results.append({
-            'url': url,
-            'title': title,
-            'content': content
-        })
+        results.append({'url': url, 'title': title, 'content': content})
 
     # parse results again if nothing is found yet
     for result in eval_xpath(dom, '//li[@class="b_algo"]'):
@@ -110,18 +101,14 @@ def response(resp):
         content = extract_text(eval_xpath(result, './/p'))
 
         # append result
-        results.append({
-            'url': url,
-            'title': title,
-            'content': content
-        })
+        results.append({'url': url, 'title': title, 'content': content})
 
     try:
         result_len_container = "".join(eval_xpath(dom, '//span[@class="sb_count"]//text()'))
         if "-" in result_len_container:
 
             # Remove the part "from-to" for paginated request ...
-            result_len_container = result_len_container[result_len_container.find("-") * 2 + 2:]
+            result_len_container = result_len_container[result_len_container.find("-") * 2 + 2 :]
 
         result_len_container = re.sub('[^0-9]', '', result_len_container)
 
diff --git a/searx/engines/bing_images.py b/searx/engines/bing_images.py
index 4bee9bc7d..246d37a30 100644
--- a/searx/engines/bing_images.py
+++ b/searx/engines/bing_images.py
@@ -9,7 +9,10 @@ from json import loads
 from searx.utils import match_language
 
 from searx.engines.bing import language_aliases
-from searx.engines.bing import _fetch_supported_languages, supported_languages_url  # NOQA # pylint: disable=unused-import
+from searx.engines.bing import (
+    _fetch_supported_languages,
+    supported_languages_url,
+)  # NOQA # pylint: disable=unused-import
 
 # about
 about = {
@@ -31,39 +34,25 @@ number_of_results = 28
 
 # search-url
 base_url = 'https://www.bing.com/'
-search_string = 'images/search'\
-    '?{query}'\
-    '&count={count}'\
-    '&first={first}'\
-    '&tsc=ImageHoverTitle'
+search_string = 'images/search' '?{query}' '&count={count}' '&first={first}' '&tsc=ImageHoverTitle'
 time_range_string = '&qft=+filterui:age-lt{interval}'
-time_range_dict = {'day': '1440',
-                   'week': '10080',
-                   'month': '43200',
-                   'year': '525600'}
+time_range_dict = {'day': '1440', 'week': '10080', 'month': '43200', 'year': '525600'}
 
 # safesearch definitions
-safesearch_types = {2: 'STRICT',
-                    1: 'DEMOTE',
-                    0: 'OFF'}
+safesearch_types = {2: 'STRICT', 1: 'DEMOTE', 0: 'OFF'}
 
 
 # do search-request
 def request(query, params):
     offset = ((params['pageno'] - 1) * number_of_results) + 1
 
-    search_path = search_string.format(
-        query=urlencode({'q': query}),
-        count=number_of_results,
-        first=offset)
+    search_path = search_string.format(query=urlencode({'q': query}), count=number_of_results, first=offset)
 
     language = match_language(params['language'], supported_languages, language_aliases).lower()
 
-    params['cookies']['SRCHHPGUSR'] = \
-        'ADLT=' + safesearch_types.get(params['safesearch'], 'DEMOTE')
+    params['cookies']['SRCHHPGUSR'] = 'ADLT=' + safesearch_types.get(params['safesearch'], 'DEMOTE')
 
-    params['cookies']['_EDGE_S'] = 'mkt=' + language +\
-        '&ui=' + language + '&F=1'
+    params['cookies']['_EDGE_S'] = 'mkt=' + language + '&ui=' + language + '&F=1'
 
     params['url'] = base_url + search_path
     if params['time_range'] in time_range_dict:
@@ -92,14 +81,18 @@ def response(resp):
             # strip 'Unicode private use area' highlighting, they render to Tux
             # the Linux penguin and a standing diamond on my machine...
             title = m.get('t', '').replace('\ue000', '').replace('\ue001', '')
-            results.append({'template': 'images.html',
-                            'url': m['purl'],
-                            'thumbnail_src': m['turl'],
-                            'img_src': m['murl'],
-                            'content': '',
-                            'title': title,
-                            'source': source,
-                            'img_format': img_format})
+            results.append(
+                {
+                    'template': 'images.html',
+                    'url': m['purl'],
+                    'thumbnail_src': m['turl'],
+                    'img_src': m['murl'],
+                    'content': '',
+                    'title': title,
+                    'source': source,
+                    'img_format': img_format,
+                }
+            )
         except:
             continue
 
diff --git a/searx/engines/bing_news.py b/searx/engines/bing_news.py
index f0bc8bead..22856541b 100644
--- a/searx/engines/bing_news.py
+++ b/searx/engines/bing_news.py
@@ -13,10 +13,7 @@ from datetime import datetime
 from dateutil import parser
 from lxml import etree
 from lxml.etree import XPath
-from searx.utils import (
-    match_language,
-    eval_xpath_getindex
-)
+from searx.utils import match_language, eval_xpath_getindex
 from searx.engines.bing import (  # pylint: disable=unused-import
     language_aliases,
     _fetch_supported_languages,
@@ -42,11 +39,8 @@ time_range_support = True
 base_url = 'https://www.bing.com/'
 search_string = 'news/search?{query}&first={offset}&format=RSS'
 search_string_with_time = 'news/search?{query}&first={offset}&qft=interval%3d"{interval}"&format=RSS'
-time_range_dict = {
-    'day': '7',
-    'week': '8',
-    'month': '9'
-}
+time_range_dict = {'day': '7', 'week': '8', 'month': '9'}
+
 
 def url_cleanup(url_string):
     """remove click"""
@@ -57,6 +51,7 @@ def url_cleanup(url_string):
         url_string = query.get('url', None)
     return url_string
 
+
 def image_url_cleanup(url_string):
     """replace the http://*bing.com/th?id=... by https://www.bing.com/th?id=..."""
 
@@ -66,6 +61,7 @@ def image_url_cleanup(url_string):
         url_string = "https://www.bing.com/th?id=" + quote(query.get('id'))
     return url_string
 
+
 def _get_url(query, language, offset, time_range):
     if time_range in time_range_dict:
         search_path = search_string_with_time.format(
@@ -91,6 +87,7 @@ def _get_url(query, language, offset, time_range):
         )
     return base_url + search_path
 
+
 def request(query, params):
 
     if params['time_range'] and params['time_range'] not in time_range_dict:
@@ -105,6 +102,7 @@ def request(query, params):
 
     return params
 
+
 def response(resp):
 
     results = []
@@ -127,26 +125,16 @@ def response(resp):
             publishedDate = datetime.now()
 
         # thumbnail
-        thumbnail = eval_xpath_getindex(
-            item, XPath('./News:Image/text()', namespaces=namespaces), 0, default=None)
+        thumbnail = eval_xpath_getindex(item, XPath('./News:Image/text()', namespaces=namespaces), 0, default=None)
         if thumbnail is not None:
             thumbnail = image_url_cleanup(thumbnail)
 
         # append result
         if thumbnail is not None:
-            results.append({
-                'url': url,
-                'title': title,
-                'publishedDate': publishedDate,
-                'content': content,
-                'img_src': thumbnail
-            })
+            results.append(
+                {'url': url, 'title': title, 'publishedDate': publishedDate, 'content': content, 'img_src': thumbnail}
+            )
         else:
-            results.append({
-                'url': url,
-                'title': title,
-                'publishedDate': publishedDate,
-                'content': content
-            })
+            results.append({'url': url, 'title': title, 'publishedDate': publishedDate, 'content': content})
 
     return results
diff --git a/searx/engines/bing_videos.py b/searx/engines/bing_videos.py
index 2e1f13de2..ad61724a1 100644
--- a/searx/engines/bing_videos.py
+++ b/searx/engines/bing_videos.py
@@ -9,7 +9,10 @@ from urllib.parse import urlencode
 from searx.utils import match_language
 
 from searx.engines.bing import language_aliases
-from searx.engines.bing import _fetch_supported_languages, supported_languages_url  # NOQA # pylint: disable=unused-import
+from searx.engines.bing import (
+    _fetch_supported_languages,
+    supported_languages_url,
+)  # NOQA # pylint: disable=unused-import
 
 # about
 about = {
@@ -28,36 +31,22 @@ time_range_support = True
 number_of_results = 28
 
 base_url = 'https://www.bing.com/'
-search_string = 'videos/search'\
-    '?{query}'\
-    '&count={count}'\
-    '&first={first}'\
-    '&scope=video'\
-    '&FORM=QBLH'
+search_string = 'videos/search' '?{query}' '&count={count}' '&first={first}' '&scope=video' '&FORM=QBLH'
 time_range_string = '&qft=+filterui:videoage-lt{interval}'
-time_range_dict = {'day': '1440',
-                   'week': '10080',
-                   'month': '43200',
-                   'year': '525600'}
+time_range_dict = {'day': '1440', 'week': '10080', 'month': '43200', 'year': '525600'}
 
 # safesearch definitions
-safesearch_types = {2: 'STRICT',
-                    1: 'DEMOTE',
-                    0: 'OFF'}
+safesearch_types = {2: 'STRICT', 1: 'DEMOTE', 0: 'OFF'}
 
 
 # do search-request
 def request(query, params):
     offset = ((params['pageno'] - 1) * number_of_results) + 1
 
-    search_path = search_string.format(
-        query=urlencode({'q': query}),
-        count=number_of_results,
-        first=offset)
+    search_path = search_string.format(query=urlencode({'q': query}), count=number_of_results, first=offset)
 
     # safesearch cookie
-    params['cookies']['SRCHHPGUSR'] = \
-        'ADLT=' + safesearch_types.get(params['safesearch'], 'DEMOTE')
+    params['cookies']['SRCHHPGUSR'] = 'ADLT=' + safesearch_types.get(params['safesearch'], 'DEMOTE')
 
     # language cookie
     language = match_language(params['language'], supported_languages, language_aliases).lower()
@@ -89,11 +78,15 @@ def response(resp):
             info = ' - '.join(result.xpath('.//div[@class="mc_vtvc_meta_block"]//span/text()')).strip()
             content = '{0} - {1}'.format(metadata['du'], info)
             thumbnail = '{0}th?id={1}'.format(base_url, metadata['thid'])
-            results.append({'url': metadata['murl'],
-                            'thumbnail': thumbnail,
-                            'title': metadata.get('vt', ''),
-                            'content': content,
-                            'template': 'videos.html'})
+            results.append(
+                {
+                    'url': metadata['murl'],
+                    'thumbnail': thumbnail,
+                    'title': metadata.get('vt', ''),
+                    'content': content,
+                    'template': 'videos.html',
+                }
+            )
 
         except:
             continue
diff --git a/searx/engines/btdigg.py b/searx/engines/btdigg.py
index cda9e9355..c5dd92105 100644
--- a/searx/engines/btdigg.py
+++ b/searx/engines/btdigg.py
@@ -11,10 +11,7 @@ from searx.utils import extract_text, get_torrent_size
 about = {
     "website": 'https://btdig.com',
     "wikidata_id": 'Q4836698',
-    "official_api_documentation": {
-        'url': 'https://btdig.com/contacts',
-        'comment': 'on demand'
-    },
+    "official_api_documentation": {'url': 'https://btdig.com/contacts', 'comment': 'on demand'},
     "use_official_api": False,
     "require_api_key": False,
     "results": 'HTML',
@@ -31,8 +28,7 @@ search_url = url + '/search?q={search_term}&p={pageno}'
 
 # do search-request
 def request(query, params):
-    params['url'] = search_url.format(search_term=quote(query),
-                                      pageno=params['pageno'] - 1)
+    params['url'] = search_url.format(search_term=quote(query), pageno=params['pageno'] - 1)
 
     return params
 
@@ -77,13 +73,17 @@ def response(resp):
         magnetlink = result.xpath('.//div[@class="torrent_magnet"]//a')[0].attrib['href']
 
         # append result
-        results.append({'url': href,
-                        'title': title,
-                        'content': content,
-                        'filesize': filesize,
-                        'files': files,
-                        'magnetlink': magnetlink,
-                        'template': 'torrent.html'})
+        results.append(
+            {
+                'url': href,
+                'title': title,
+                'content': content,
+                'filesize': filesize,
+                'files': files,
+                'magnetlink': magnetlink,
+                'template': 'torrent.html',
+            }
+        )
 
     # return results sorted by seeder
     return results
diff --git a/searx/engines/ccengine.py b/searx/engines/ccengine.py
index 6f3a5adb7..93ac30c86 100644
--- a/searx/engines/ccengine.py
+++ b/searx/engines/ccengine.py
@@ -29,10 +29,7 @@ search_string = '&page={page}&page_size={nb_per_page}&format=json&{query}'
 
 def request(query, params):
 
-    search_path = search_string.format(
-        query=urlencode({'q': query}),
-        nb_per_page=nb_per_page,
-        page=params['pageno'])
+    search_path = search_string.format(query=urlencode({'q': query}), nb_per_page=nb_per_page, page=params['pageno'])
 
     params['url'] = base_url + search_path
 
@@ -45,9 +42,13 @@ def response(resp):
     json_data = loads(resp.text)
 
     for result in json_data['results']:
-        results.append({'url': result['foreign_landing_url'],
-                        'title': result['title'],
-                        'img_src': result['url'],
-                        'template': 'images.html'})
+        results.append(
+            {
+                'url': result['foreign_landing_url'],
+                'title': result['title'],
+                'img_src': result['url'],
+                'template': 'images.html',
+            }
+        )
 
     return results
diff --git a/searx/engines/command.py b/searx/engines/command.py
index aca379c67..abd29e2a5 100644
--- a/searx/engines/command.py
+++ b/searx/engines/command.py
@@ -138,7 +138,7 @@ def __check_query_params(params):
 
 
 def check_parsing_options(engine_settings):
-    """ Checks if delimiter based parsing or regex parsing is configured correctly """
+    """Checks if delimiter based parsing or regex parsing is configured correctly"""
 
     if 'delimiter' not in engine_settings and 'parse_regex' not in engine_settings:
         raise ValueError('failed to init settings for parsing lines: missing delimiter or parse_regex')
@@ -151,7 +151,7 @@ def check_parsing_options(engine_settings):
 
 
 def __parse_single_result(raw_result):
-    """ Parses command line output based on configuration """
+    """Parses command line output based on configuration"""
 
     result = {}
 
@@ -167,6 +167,6 @@ def __parse_single_result(raw_result):
             found = regex.search(raw_result)
             if not found:
                 return {}
-            result[result_key] = raw_result[found.start():found.end()]
+            result[result_key] = raw_result[found.start() : found.end()]
 
     return result
diff --git a/searx/engines/core.py b/searx/engines/core.py
index e83c8bbe9..1fcb68f1f 100644
--- a/searx/engines/core.py
+++ b/searx/engines/core.py
@@ -28,22 +28,24 @@ api_key = 'unset'
 base_url = 'https://core.ac.uk:443/api-v2/search/'
 search_string = '{query}?page={page}&pageSize={nb_per_page}&apiKey={apikey}'
 
+
 def request(query, params):
 
     if api_key == 'unset':
         raise SearxEngineAPIException('missing CORE API key')
 
     search_path = search_string.format(
-        query = urlencode({'q': query}),
-        nb_per_page = nb_per_page,
-        page = params['pageno'],
-        apikey = api_key,
+        query=urlencode({'q': query}),
+        nb_per_page=nb_per_page,
+        page=params['pageno'],
+        apikey=api_key,
     )
     params['url'] = base_url + search_path
 
     logger.debug("query_url --> %s", params['url'])
     return params
 
+
 def response(resp):
     results = []
     json_data = loads(resp.text)
@@ -52,7 +54,7 @@ def response(resp):
 
         source = result['_source']
         time = source['publishedDate'] or source['depositedDate']
-        if time :
+        if time:
             date = datetime.fromtimestamp(time / 1000)
         else:
             date = None
@@ -66,12 +68,14 @@ def response(resp):
             metadata.append(source['doi'])
         metadata = ' / '.join(metadata)
 
-        results.append({
-            'url': source['urls'][0].replace('http://', 'https://', 1),
-            'title': source['title'],
-            'content': source['description'],
-            'publishedDate': date,
-            'metadata' : metadata,
-        })
+        results.append(
+            {
+                'url': source['urls'][0].replace('http://', 'https://', 1),
+                'title': source['title'],
+                'content': source['description'],
+                'publishedDate': date,
+                'metadata': metadata,
+            }
+        )
 
     return results
diff --git a/searx/engines/currency_convert.py b/searx/engines/currency_convert.py
index d4c3b5f81..969688126 100644
--- a/searx/engines/currency_convert.py
+++ b/searx/engines/currency_convert.py
@@ -30,7 +30,7 @@ def request(query, params):
 
 def response(resp):
     """remove first and last lines to get only json"""
-    json_resp = resp.text[resp.text.find('\n') + 1:resp.text.rfind('\n') - 2]
+    json_resp = resp.text[resp.text.find('\n') + 1 : resp.text.rfind('\n') - 2]
     results = []
     try:
         conversion_rate = float(json.loads(json_resp)['conversion']['converted-amount'])
@@ -47,7 +47,8 @@ def response(resp):
     )
 
     url = 'https://duckduckgo.com/js/spice/currency/1/{0}/{1}'.format(
-        resp.search_params['from'].upper(), resp.search_params['to'])
+        resp.search_params['from'].upper(), resp.search_params['to']
+    )
 
     results.append({'answer': answer, 'url': url})
 
diff --git a/searx/engines/dailymotion.py b/searx/engines/dailymotion.py
index 92d368c11..5607691a4 100644
--- a/searx/engines/dailymotion.py
+++ b/searx/engines/dailymotion.py
@@ -25,8 +25,10 @@ paging = True
 # search-url
 # see http://www.dailymotion.com/doc/api/obj-video.html
 search_url = 'https://api.dailymotion.com/videos?fields=created_time,title,description,duration,url,thumbnail_360_url,id&sort=relevance&limit=5&page={pageno}&{query}'  # noqa
-embedded_url = '<iframe frameborder="0" width="540" height="304" ' +\
-    'data-src="https://www.dailymotion.com/embed/video/{videoid}" allowfullscreen></iframe>'
+embedded_url = (
+    '<iframe frameborder="0" width="540" height="304" '
+    + 'data-src="https://www.dailymotion.com/embed/video/{videoid}" allowfullscreen></iframe>'
+)
 
 supported_languages_url = 'https://api.dailymotion.com/languages'
 
@@ -39,8 +41,8 @@ def request(query, params):
         locale = match_language(params['language'], supported_languages)
 
     params['url'] = search_url.format(
-        query=urlencode({'search': query, 'localization': locale}),
-        pageno=params['pageno'])
+        query=urlencode({'search': query, 'localization': locale}), pageno=params['pageno']
+    )
 
     return params
 
@@ -67,13 +69,17 @@ def response(resp):
         # http to https
         thumbnail = thumbnail.replace("http://", "https://")
 
-        results.append({'template': 'videos.html',
-                        'url': url,
-                        'title': title,
-                        'content': content,
-                        'publishedDate': publishedDate,
-                        'embedded': embedded,
-                        'thumbnail': thumbnail})
+        results.append(
+            {
+                'template': 'videos.html',
+                'url': url,
+                'title': title,
+                'content': content,
+                'publishedDate': publishedDate,
+                'embedded': embedded,
+                'thumbnail': thumbnail,
+            }
+        )
 
     # return results
     return results
diff --git a/searx/engines/deezer.py b/searx/engines/deezer.py
index 946bd3ebe..220ac599d 100644
--- a/searx/engines/deezer.py
+++ b/searx/engines/deezer.py
@@ -24,9 +24,11 @@ paging = True
 url = 'https://api.deezer.com/'
 search_url = url + 'search?{query}&index={offset}'
 
-embedded_url = '<iframe scrolling="no" frameborder="0" allowTransparency="true" ' +\
-    'data-src="https://www.deezer.com/plugins/player?type=tracks&id={audioid}" ' +\
-    'width="540" height="80"></iframe>'
+embedded_url = (
+    '<iframe scrolling="no" frameborder="0" allowTransparency="true" '
+    + 'data-src="https://www.deezer.com/plugins/player?type=tracks&id={audioid}" '
+    + 'width="540" height="80"></iframe>'
+)
 
 
 # do search-request
@@ -53,18 +55,12 @@ def response(resp):
             if url.startswith('http://'):
                 url = 'https' + url[4:]
 
-            content = '{} - {} - {}'.format(
-                result['artist']['name'],
-                result['album']['title'],
-                result['title'])
+            content = '{} - {} - {}'.format(result['artist']['name'], result['album']['title'], result['title'])
 
             embedded = embedded_url.format(audioid=result['id'])
 
             # append result
-            results.append({'url': url,
-                            'title': title,
-                            'embedded': embedded,
-                            'content': content})
+            results.append({'url': url, 'title': title, 'embedded': embedded, 'content': content})
 
     # return results
     return results
diff --git a/searx/engines/demo_offline.py b/searx/engines/demo_offline.py
index a4a632180..aeb74f443 100644
--- a/searx/engines/demo_offline.py
+++ b/searx/engines/demo_offline.py
@@ -31,6 +31,7 @@ about = {
 # if there is a need for globals, use a leading underline
 _my_offline_engine = None
 
+
 def init(engine_settings=None):
     """Initialization of the (offline) engine.  The origin of this demo engine is a
     simple json string which is loaded in this example while the engine is
@@ -44,11 +45,10 @@ def init(engine_settings=None):
         ', {"value":"first item"}'
         ', {"value":"second item"}'
         ', {"value":"third item"}'
-        ']'
-
-        % engine_settings.get('name')
+        ']' % engine_settings.get('name')
     )
 
+
 def search(query, request_params):
     """Query (offline) engine and return results.  Assemble the list of results from
     your local engine.  In this demo engine we ignore the 'query' term, usual
@@ -62,11 +62,11 @@ def search(query, request_params):
 
     for row in result_list:
         entry = {
-            'query' : query,
-            'language' : request_params['language'],
-            'value' : row.get("value"),
+            'query': query,
+            'language': request_params['language'],
+            'value': row.get("value"),
             # choose a result template or comment out to use the *default*
-            'template' : 'key-value.html',
+            'template': 'key-value.html',
         }
         ret_val.append(entry)
 
diff --git a/searx/engines/demo_online.py b/searx/engines/demo_online.py
index a0f736e42..e53b3c15e 100644
--- a/searx/engines/demo_online.py
+++ b/searx/engines/demo_online.py
@@ -43,6 +43,7 @@ about = {
 # if there is a need for globals, use a leading underline
 _my_online_engine = None
 
+
 def init(engine_settings):
     """Initialization of the (online) engine.  If no initialization is needed, drop
     this init function.
@@ -51,20 +52,24 @@ def init(engine_settings):
     global _my_online_engine  # pylint: disable=global-statement
     _my_online_engine = engine_settings.get('name')
 
+
 def request(query, params):
     """Build up the ``params`` for the online request.  In this example we build a
     URL to fetch images from `artic.edu <https://artic.edu>`__
 
     """
-    args = urlencode({
-        'q' : query,
-        'page' : params['pageno'],
-        'fields' : 'id,title,artist_display,medium_display,image_id,date_display,dimensions,artist_titles',
-        'limit' : page_size,
-        })
+    args = urlencode(
+        {
+            'q': query,
+            'page': params['pageno'],
+            'fields': 'id,title,artist_display,medium_display,image_id,date_display,dimensions,artist_titles',
+            'limit': page_size,
+        }
+    )
     params['url'] = search_api + args
     return params
 
+
 def response(resp):
     """Parse out the result items from the response.  In this example we parse the
     response from `api.artic.edu <https://artic.edu>`__ and filter out all
@@ -79,14 +84,16 @@ def response(resp):
         if not result['image_id']:
             continue
 
-        results.append({
-            'url': 'https://artic.edu/artworks/%(id)s' % result,
-            'title': result['title'] + " (%(date_display)s) //  %(artist_display)s" % result,
-            'content': result['medium_display'],
-            'author': ', '.join(result['artist_titles']),
-            'img_src': image_api + '/%(image_id)s/full/843,/0/default.jpg' % result,
-            'img_format': result['dimensions'],
-            'template': 'images.html'
-        })
+        results.append(
+            {
+                'url': 'https://artic.edu/artworks/%(id)s' % result,
+                'title': result['title'] + " (%(date_display)s) //  %(artist_display)s" % result,
+                'content': result['medium_display'],
+                'author': ', '.join(result['artist_titles']),
+                'img_src': image_api + '/%(image_id)s/full/843,/0/default.jpg' % result,
+                'img_format': result['dimensions'],
+                'template': 'images.html',
+            }
+        )
 
     return results
diff --git a/searx/engines/deviantart.py b/searx/engines/deviantart.py
index b13d54dd5..e44ac28e5 100644
--- a/searx/engines/deviantart.py
+++ b/searx/engines/deviantart.py
@@ -32,13 +32,14 @@ time_range_dict = {
 # search-url
 base_url = 'https://www.deviantart.com'
 
+
 def request(query, params):
 
     # https://www.deviantart.com/search/deviations?page=5&q=foo
 
-    query =  {
-        'page' : params['pageno'],
-        'q'    : query,
+    query = {
+        'page': params['pageno'],
+        'q': query,
     }
     if params['time_range'] in time_range_dict:
         query['order'] = time_range_dict[params['time_range']]
@@ -47,6 +48,7 @@ def request(query, params):
 
     return params
 
+
 def response(resp):
 
     results = []
@@ -67,11 +69,13 @@ def response(resp):
                 continue
             img_tag = img_tag[0]
 
-            results.append({
-                'template': 'images.html',
-                'url': a_tag.attrib.get('href'),
-                'img_src': img_tag.attrib.get('src'),
-                'title': img_tag.attrib.get('alt'),
-            })
+            results.append(
+                {
+                    'template': 'images.html',
+                    'url': a_tag.attrib.get('href'),
+                    'img_src': img_tag.attrib.get('src'),
+                    'title': img_tag.attrib.get('alt'),
+                }
+            )
 
     return results
diff --git a/searx/engines/dictzone.py b/searx/engines/dictzone.py
index 4a92a22c3..126e75374 100644
--- a/searx/engines/dictzone.py
+++ b/searx/engines/dictzone.py
@@ -27,9 +27,7 @@ https_support = True
 
 
 def request(query, params):
-    params['url'] = url.format(from_lang=params['from_lang'][2],
-                               to_lang=params['to_lang'][2],
-                               query=params['query'])
+    params['url'] = url.format(from_lang=params['from_lang'][2], to_lang=params['to_lang'][2], query=params['query'])
 
     return params
 
@@ -51,10 +49,12 @@ def response(resp):
             if t.strip():
                 to_results.append(to_result.text_content())
 
-        results.append({
-            'url': urljoin(str(resp.url), '?%d' % k),
-            'title': from_result.text_content(),
-            'content': '; '.join(to_results)
-        })
+        results.append(
+            {
+                'url': urljoin(str(resp.url), '?%d' % k),
+                'title': from_result.text_content(),
+                'content': '; '.join(to_results),
+            }
+        )
 
     return results
diff --git a/searx/engines/digbt.py b/searx/engines/digbt.py
index 109662a49..2914e9228 100644
--- a/searx/engines/digbt.py
+++ b/searx/engines/digbt.py
@@ -48,13 +48,17 @@ def response(resp):
         filesize = get_torrent_size(files_data[FILESIZE], files_data[FILESIZE_MULTIPLIER])
         magnetlink = result.xpath('.//div[@class="tail"]//a[@class="title"]/@href')[0]
 
-        results.append({'url': url,
-                        'title': title,
-                        'content': content,
-                        'filesize': filesize,
-                        'magnetlink': magnetlink,
-                        'seed': 'N/A',
-                        'leech': 'N/A',
-                        'template': 'torrent.html'})
+        results.append(
+            {
+                'url': url,
+                'title': title,
+                'content': content,
+                'filesize': filesize,
+                'magnetlink': magnetlink,
+                'seed': 'N/A',
+                'leech': 'N/A',
+                'template': 'torrent.html',
+            }
+        )
 
     return results
diff --git a/searx/engines/docker_hub.py b/searx/engines/docker_hub.py
index e69f677b3..1e492b196 100644
--- a/searx/engines/docker_hub.py
+++ b/searx/engines/docker_hub.py
@@ -9,13 +9,13 @@ from urllib.parse import urlencode
 from dateutil import parser
 
 about = {
-     "website": 'https://hub.docker.com',
-     "wikidata_id": 'Q100769064',
-     "official_api_documentation": 'https://docs.docker.com/registry/spec/api/',
-     "use_official_api": True,
-     "require_api_key": False,
-     "results": 'JSON',
- }
+    "website": 'https://hub.docker.com',
+    "wikidata_id": 'Q100769064',
+    "official_api_documentation": 'https://docs.docker.com/registry/spec/api/',
+    "use_official_api": True,
+    "require_api_key": False,
+    "results": 'JSON',
+}
 
 categories = ['it']  # optional
 paging = True
@@ -23,6 +23,7 @@ paging = True
 base_url = "https://hub.docker.com/"
 search_url = base_url + "api/content/v1/products/search?{query}&type=image&page_size=25"
 
+
 def request(query, params):
 
     params['url'] = search_url.format(query=urlencode(dict(q=query, page=params["pageno"])))
@@ -30,6 +31,7 @@ def request(query, params):
 
     return params
 
+
 def response(resp):
     '''post-response callback
     resp: requests response object
@@ -53,12 +55,8 @@ def response(resp):
                 result["url"] = base_url + "r/" + item.get('slug', "")
             result["title"] = item.get("name")
             result["content"] = item.get("short_description")
-            result["publishedDate"] = parser.parse(
-                item.get("updated_at") or item.get("created_at")
-            )
-            result["thumbnail"] = (
-                item["logo_url"].get("large") or item["logo_url"].get("small")
-            )
+            result["publishedDate"] = parser.parse(item.get("updated_at") or item.get("created_at"))
+            result["thumbnail"] = item["logo_url"].get("large") or item["logo_url"].get("small")
             results.append(result)
 
     return results
diff --git a/searx/engines/doku.py b/searx/engines/doku.py
index cf38b3b9a..e81131cce 100644
--- a/searx/engines/doku.py
+++ b/searx/engines/doku.py
@@ -25,8 +25,7 @@ number_of_results = 5
 # search-url
 # Doku is OpenSearch compatible
 base_url = 'http://localhost:8090'
-search_url = '/?do=search'\
-             '&{query}'
+search_url = '/?do=search' '&{query}'
 # TODO             '&startRecord={offset}'\
 # TODO             '&maximumRecords={limit}'\
 
@@ -34,8 +33,7 @@ search_url = '/?do=search'\
 # do search-request
 def request(query, params):
 
-    params['url'] = base_url +\
-        search_url.format(query=urlencode({'id': query}))
+    params['url'] = base_url + search_url.format(query=urlencode({'id': query}))
 
     return params
 
@@ -60,9 +58,7 @@ def response(resp):
         title = extract_text(eval_xpath(r, './/a[@class="wikilink1"]/@title'))
 
         # append result
-        results.append({'title': title,
-                        'content': "",
-                        'url': base_url + res_url})
+        results.append({'title': title, 'content': "", 'url': base_url + res_url})
 
     # Search results
     for r in eval_xpath(doc, '//dl[@class="search_results"]/*'):
@@ -74,9 +70,7 @@ def response(resp):
                 content = extract_text(eval_xpath(r, '.'))
 
                 # append result
-                results.append({'title': title,
-                                'content': content,
-                                'url': base_url + res_url})
+                results.append({'title': title, 'content': content, 'url': base_url + res_url})
         except:
             continue
 
diff --git a/searx/engines/duckduckgo.py b/searx/engines/duckduckgo.py
index d283af81d..0d2a524df 100644
--- a/searx/engines/duckduckgo.py
+++ b/searx/engines/duckduckgo.py
@@ -39,15 +39,10 @@ language_aliases = {
     'ko': 'kr-KR',
     'sl-SI': 'sl-SL',
     'zh-TW': 'tzh-TW',
-    'zh-HK': 'tzh-HK'
+    'zh-HK': 'tzh-HK',
 }
 
-time_range_dict = {
-    'day': 'd',
-    'week': 'w',
-    'month': 'm',
-    'year': 'y'
-}
+time_range_dict = {'day': 'd', 'week': 'w', 'month': 'm', 'year': 'y'}
 
 # search-url
 url = 'https://lite.duckduckgo.com/lite'
@@ -118,6 +113,7 @@ def request(query, params):
     logger.debug("param cookies: %s", params['cookies'])
     return params
 
+
 # get response from search-request
 def response(resp):
 
@@ -163,21 +159,24 @@ def response(resp):
         if td_content is None:
             continue
 
-        results.append({
-            'title': a_tag.text_content(),
-            'content': extract_text(td_content),
-            'url': a_tag.get('href'),
-        })
+        results.append(
+            {
+                'title': a_tag.text_content(),
+                'content': extract_text(td_content),
+                'url': a_tag.get('href'),
+            }
+        )
 
     return results
 
+
 # get supported languages from their site
 def _fetch_supported_languages(resp):
 
     # response is a js file with regions as an embedded object
     response_page = resp.text
-    response_page = response_page[response_page.find('regions:{') + 8:]
-    response_page = response_page[:response_page.find('}') + 1]
+    response_page = response_page[response_page.find('regions:{') + 8 :]
+    response_page = response_page[: response_page.find('}') + 1]
 
     regions_json = loads(response_page)
     supported_languages = map((lambda x: x[3:] + '-' + x[:2].upper()), regions_json.keys())
diff --git a/searx/engines/duckduckgo_definitions.py b/searx/engines/duckduckgo_definitions.py
index 3ef043964..d4e813c2b 100644
--- a/searx/engines/duckduckgo_definitions.py
+++ b/searx/engines/duckduckgo_definitions.py
@@ -10,7 +10,10 @@ from lxml import html
 
 from searx.data import WIKIDATA_UNITS
 from searx.engines.duckduckgo import language_aliases
-from searx.engines.duckduckgo import _fetch_supported_languages, supported_languages_url  # NOQA # pylint: disable=unused-import
+from searx.engines.duckduckgo import (
+    _fetch_supported_languages,
+    supported_languages_url,
+)  # NOQA # pylint: disable=unused-import
 from searx.utils import extract_text, html_to_text, match_language, get_string_replaces_function
 from searx.external_urls import get_external_url, get_earth_coordinates_url, area_to_osm_zoom
 
@@ -24,19 +27,15 @@ about = {
     "results": 'JSON',
 }
 
-URL = 'https://api.duckduckgo.com/'\
-    + '?{query}&format=json&pretty=0&no_redirect=1&d=1'
+URL = 'https://api.duckduckgo.com/' + '?{query}&format=json&pretty=0&no_redirect=1&d=1'
 
-WIKIDATA_PREFIX = [
-    'http://www.wikidata.org/entity/',
-    'https://www.wikidata.org/entity/'
-]
+WIKIDATA_PREFIX = ['http://www.wikidata.org/entity/', 'https://www.wikidata.org/entity/']
 
 replace_http_by_https = get_string_replaces_function({'http:': 'https:'})
 
 
 def is_broken_text(text):
-    """ duckduckgo may return something like "<a href="xxxx">http://somewhere Related website<a/>"
+    """duckduckgo may return something like "<a href="xxxx">http://somewhere Related website<a/>"
 
     The href URL is broken, the "Related website" may contains some HTML.
 
@@ -61,11 +60,7 @@ def result_to_text(text, htmlResult):
 
 def request(query, params):
     params['url'] = URL.format(query=urlencode({'q': query}))
-    language = match_language(
-        params['language'],
-        supported_languages,
-        language_aliases
-    )
+    language = match_language(params['language'], supported_languages, language_aliases)
     language = language.split('-')[0]
     params['headers']['Accept-Language'] = language
     return params
@@ -127,23 +122,14 @@ def response(resp):
             firstURL = ddg_result.get('FirstURL')
             text = ddg_result.get('Text')
             if not is_broken_text(text):
-                suggestion = result_to_text(
-                    text,
-                    ddg_result.get('Result')
-                )
+                suggestion = result_to_text(text, ddg_result.get('Result'))
                 if suggestion != heading and suggestion is not None:
                     results.append({'suggestion': suggestion})
         elif 'Topics' in ddg_result:
             suggestions = []
-            relatedTopics.append({
-                'name': ddg_result.get('Name', ''),
-                'suggestions': suggestions
-            })
+            relatedTopics.append({'name': ddg_result.get('Name', ''), 'suggestions': suggestions})
             for topic_result in ddg_result.get('Topics', []):
-                suggestion = result_to_text(
-                    topic_result.get('Text'),
-                    topic_result.get('Result')
-                )
+                suggestion = result_to_text(topic_result.get('Text'), topic_result.get('Result'))
                 if suggestion != heading and suggestion is not None:
                     suggestions.append(suggestion)
 
@@ -152,25 +138,15 @@ def response(resp):
     if abstractURL != '':
         # add as result ? problem always in english
         infobox_id = abstractURL
-        urls.append({
-            'title': search_res.get('AbstractSource'),
-            'url': abstractURL,
-            'official': True
-        })
-        results.append({
-            'url': abstractURL,
-            'title': heading
-        })
+        urls.append({'title': search_res.get('AbstractSource'), 'url': abstractURL, 'official': True})
+        results.append({'url': abstractURL, 'title': heading})
 
     # definition
     definitionURL = search_res.get('DefinitionURL', '')
     if definitionURL != '':
         # add as result ? as answer ? problem always in english
         infobox_id = definitionURL
-        urls.append({
-            'title': search_res.get('DefinitionSource'),
-            'url': definitionURL
-        })
+        urls.append({'title': search_res.get('DefinitionSource'), 'url': definitionURL})
 
     # to merge with wikidata's infobox
     if infobox_id:
@@ -198,10 +174,7 @@ def response(resp):
                 # * netflix_id
                 external_url = get_external_url(data_type, data_value)
                 if external_url is not None:
-                    urls.append({
-                        'title': data_label,
-                        'url': external_url
-                    })
+                    urls.append({'title': data_label, 'url': external_url})
                 elif data_type in ['instance', 'wiki_maps_trigger', 'google_play_artist_id']:
                     # ignore instance: Wikidata value from "Instance Of" (Qxxxx)
                     # ignore wiki_maps_trigger: reference to a javascript
@@ -211,11 +184,7 @@ def response(resp):
                     # There is already an URL for the website
                     pass
                 elif data_type == 'area':
-                    attributes.append({
-                        'label': data_label,
-                        'value': area_to_str(data_value),
-                        'entity': 'P2046'
-                    })
+                    attributes.append({'label': data_label, 'value': area_to_str(data_value), 'entity': 'P2046'})
                     osm_zoom = area_to_osm_zoom(data_value.get('amount'))
                 elif data_type == 'coordinates':
                     if data_value.get('globe') == 'http://www.wikidata.org/entity/Q2':
@@ -224,16 +193,9 @@ def response(resp):
                         coordinates = info
                     else:
                         # coordinate NOT on Earth
-                        attributes.append({
-                            'label': data_label,
-                            'value': data_value,
-                            'entity': 'P625'
-                        })
+                        attributes.append({'label': data_label, 'value': data_value, 'entity': 'P625'})
                 elif data_type == 'string':
-                    attributes.append({
-                        'label': data_label,
-                        'value': data_value
-                    })
+                    attributes.append({'label': data_label, 'value': data_value})
 
             if coordinates:
                 data_label = coordinates.get('label')
@@ -241,31 +203,24 @@ def response(resp):
                 latitude = data_value.get('latitude')
                 longitude = data_value.get('longitude')
                 url = get_earth_coordinates_url(latitude, longitude, osm_zoom)
-                urls.append({
-                    'title': 'OpenStreetMap',
-                    'url': url,
-                    'entity': 'P625'
-                })
+                urls.append({'title': 'OpenStreetMap', 'url': url, 'entity': 'P625'})
 
     if len(heading) > 0:
         # TODO get infobox.meta.value where .label='article_title'    # pylint: disable=fixme
-        if image is None and len(attributes) == 0 and len(urls) == 1 and\
-           len(relatedTopics) == 0 and len(content) == 0:
-            results.append({
-                'url': urls[0]['url'],
-                'title': heading,
-                'content': content
-            })
+        if image is None and len(attributes) == 0 and len(urls) == 1 and len(relatedTopics) == 0 and len(content) == 0:
+            results.append({'url': urls[0]['url'], 'title': heading, 'content': content})
         else:
-            results.append({
-                'infobox': heading,
-                'id': infobox_id,
-                'content': content,
-                'img_src': image,
-                'attributes': attributes,
-                'urls': urls,
-                'relatedTopics': relatedTopics
-            })
+            results.append(
+                {
+                    'infobox': heading,
+                    'id': infobox_id,
+                    'content': content,
+                    'img_src': image,
+                    'attributes': attributes,
+                    'urls': urls,
+                    'relatedTopics': relatedTopics,
+                }
+            )
 
     return results
 
@@ -273,7 +228,7 @@ def response(resp):
 def unit_to_str(unit):
     for prefix in WIKIDATA_PREFIX:
         if unit.startswith(prefix):
-            wikidata_entity = unit[len(prefix):]
+            wikidata_entity = unit[len(prefix) :]
             return WIKIDATA_UNITS.get(wikidata_entity, unit)
     return unit
 
diff --git a/searx/engines/duckduckgo_images.py b/searx/engines/duckduckgo_images.py
index 0daaf41e9..21e24d2c9 100644
--- a/searx/engines/duckduckgo_images.py
+++ b/searx/engines/duckduckgo_images.py
@@ -7,7 +7,10 @@ from json import loads
 from urllib.parse import urlencode
 from searx.exceptions import SearxEngineAPIException
 from searx.engines.duckduckgo import get_region_code
-from searx.engines.duckduckgo import _fetch_supported_languages, supported_languages_url  # NOQA # pylint: disable=unused-import
+from searx.engines.duckduckgo import (
+    _fetch_supported_languages,
+    supported_languages_url,
+)  # NOQA # pylint: disable=unused-import
 from searx.network import get
 
 # about
@@ -41,8 +44,8 @@ def get_vqd(query, headers):
     content = res.text
     if content.find('vqd=\'') == -1:
         raise SearxEngineAPIException('Request failed')
-    vqd = content[content.find('vqd=\'') + 5:]
-    vqd = vqd[:vqd.find('\'')]
+    vqd = content[content.find('vqd=\'') + 5 :]
+    vqd = vqd[: vqd.find('\'')]
     return vqd
 
 
@@ -61,10 +64,10 @@ def request(query, params):
     region_code = get_region_code(params['language'], lang_list=supported_languages)
     if region_code:
         params['url'] = images_url.format(
-            query=urlencode({'q': query, 'l': region_code}), offset=offset, safesearch=safesearch, vqd=vqd)
+            query=urlencode({'q': query, 'l': region_code}), offset=offset, safesearch=safesearch, vqd=vqd
+        )
     else:
-        params['url'] = images_url.format(
-            query=urlencode({'q': query}), offset=offset, safesearch=safesearch, vqd=vqd)
+        params['url'] = images_url.format(query=urlencode({'q': query}), offset=offset, safesearch=safesearch, vqd=vqd)
 
     return params
 
@@ -84,11 +87,15 @@ def response(resp):
         image = result['image']
 
         # append result
-        results.append({'template': 'images.html',
-                        'title': title,
-                        'content': '',
-                        'thumbnail_src': thumbnail,
-                        'img_src': image,
-                        'url': url})
+        results.append(
+            {
+                'template': 'images.html',
+                'title': title,
+                'content': '',
+                'thumbnail_src': thumbnail,
+                'img_src': image,
+                'url': url,
+            }
+        )
 
     return results
diff --git a/searx/engines/duden.py b/searx/engines/duden.py
index bc4211c67..600b61f3c 100644
--- a/searx/engines/duden.py
+++ b/searx/engines/duden.py
@@ -38,7 +38,7 @@ def request(query, params):
       pageno  : 1 # number of the requested page
     '''
 
-    offset = (params['pageno'] - 1)
+    offset = params['pageno'] - 1
     if offset == 0:
         search_url_fmt = base_url + 'suchen/dudenonline/{query}'
         params['url'] = search_url_fmt.format(query=quote(query))
@@ -58,9 +58,9 @@ def response(resp):
 
     dom = html.fromstring(resp.text)
 
-    number_of_results_element =\
-        eval_xpath_getindex(dom, '//a[@class="active" and contains(@href,"/suchen/dudenonline")]/span/text()',
-                            0, default=None)
+    number_of_results_element = eval_xpath_getindex(
+        dom, '//a[@class="active" and contains(@href,"/suchen/dudenonline")]/span/text()', 0, default=None
+    )
     if number_of_results_element is not None:
         number_of_results_string = re.sub('[^0-9]', '', number_of_results_element)
         results.append({'number_of_results': int(number_of_results_string)})
@@ -71,8 +71,6 @@ def response(resp):
         title = eval_xpath(result, 'string(.//h2/a)').strip()
         content = extract_text(eval_xpath(result, './/p'))
         # append result
-        results.append({'url': url,
-                        'title': title,
-                        'content': content})
+        results.append({'url': url, 'title': title, 'content': content})
 
     return results
diff --git a/searx/engines/dummy-offline.py b/searx/engines/dummy-offline.py
index cf2f75312..632eeb2b3 100644
--- a/searx/engines/dummy-offline.py
+++ b/searx/engines/dummy-offline.py
@@ -15,6 +15,8 @@ about = {
 
 
 def search(query, request_params):
-    return [{
-        'result': 'this is what you get',
-    }]
+    return [
+        {
+            'result': 'this is what you get',
+        }
+    ]
diff --git a/searx/engines/ebay.py b/searx/engines/ebay.py
index 45c633b42..b7aefcb44 100644
--- a/searx/engines/ebay.py
+++ b/searx/engines/ebay.py
@@ -58,16 +58,17 @@ def response(resp):
         if title == "":
             continue
 
-        results.append({
-            'url': url,
-            'title': title,
-            'content': content,
-            'price': price,
-            'shipping': shipping,
-            'source_country': source_country,
-            'thumbnail': thumbnail,
-            'template': 'products.html',
-
-        })
+        results.append(
+            {
+                'url': url,
+                'title': title,
+                'content': content,
+                'price': price,
+                'shipping': shipping,
+                'source_country': source_country,
+                'thumbnail': thumbnail,
+                'template': 'products.html',
+            }
+        )
 
     return results
diff --git a/searx/engines/elasticsearch.py b/searx/engines/elasticsearch.py
index db84a5c13..f6e207b4d 100644
--- a/searx/engines/elasticsearch.py
+++ b/searx/engines/elasticsearch.py
@@ -119,9 +119,7 @@ def response(resp):
         r['template'] = 'key-value.html'
 
         if show_metadata:
-            r['metadata'] = {'index': result['_index'],
-                             'id': result['_id'],
-                             'score': result['_score']}
+            r['metadata'] = {'index': result['_index'], 'id': result['_id'], 'score': result['_score']}
 
         results.append(r)
 
@@ -133,12 +131,10 @@ _available_query_types = {
     # https://www.elastic.co/guide/en/elasticsearch/reference/current/full-text-queries.html
     'match': _match_query,
     'simple_query_string': _simple_query_string_query,
-
     # Term-level queries
     # https://www.elastic.co/guide/en/elasticsearch/reference/current/term-level-queries.html
     'term': _term_query,
     'terms': _terms_query,
-
     # Query JSON defined by the instance administrator.
     'custom': _custom_query,
 }
diff --git a/searx/engines/etools.py b/searx/engines/etools.py
index bf4f4ea1f..c66ceeb4b 100644
--- a/searx/engines/etools.py
+++ b/searx/engines/etools.py
@@ -22,10 +22,7 @@ paging = False
 safesearch = True
 
 base_url = 'https://www.etools.ch'
-search_path = '/searchAdvancedSubmit.do'\
-    '?query={search_term}'\
-    '&pageResults=20'\
-    '&safeSearch={safesearch}'
+search_path = '/searchAdvancedSubmit.do' '?query={search_term}' '&pageResults=20' '&safeSearch={safesearch}'
 
 
 def request(query, params):
@@ -49,8 +46,6 @@ def response(resp):
         title = extract_text(eval_xpath(result, './a//text()'))
         content = extract_text(eval_xpath(result, './/div[@class="text"]//text()'))
 
-        results.append({'url': url,
-                        'title': title,
-                        'content': content})
+        results.append({'url': url, 'title': title, 'content': content})
 
     return results
diff --git a/searx/engines/fdroid.py b/searx/engines/fdroid.py
index 8fff2e384..c381b25d4 100644
--- a/searx/engines/fdroid.py
+++ b/searx/engines/fdroid.py
@@ -42,13 +42,13 @@ def response(resp):
     for app in dom.xpath('//a[@class="package-header"]'):
         app_url = app.xpath('./@href')[0]
         app_title = extract_text(app.xpath('./div/h4[@class="package-name"]/text()'))
-        app_content = extract_text(app.xpath('./div/div/span[@class="package-summary"]')).strip() \
-            + ' - ' + extract_text(app.xpath('./div/div/span[@class="package-license"]')).strip()
+        app_content = (
+            extract_text(app.xpath('./div/div/span[@class="package-summary"]')).strip()
+            + ' - '
+            + extract_text(app.xpath('./div/div/span[@class="package-license"]')).strip()
+        )
         app_img_src = app.xpath('./img[@class="package-icon"]/@src')[0]
 
-        results.append({'url': app_url,
-                        'title': app_title,
-                        'content': app_content,
-                        'img_src': app_img_src})
+        results.append({'url': app_url, 'title': app_title, 'content': app_content, 'img_src': app_img_src})
 
     return results
diff --git a/searx/engines/flickr.py b/searx/engines/flickr.py
index b0ddf6224..b7cd76808 100644
--- a/searx/engines/flickr.py
+++ b/searx/engines/flickr.py
@@ -25,10 +25,12 @@ paging = True
 api_key = None
 
 
-url = 'https://api.flickr.com/services/rest/?method=flickr.photos.search' +\
-      '&api_key={api_key}&{text}&sort=relevance' +\
-      '&extras=description%2C+owner_name%2C+url_o%2C+url_n%2C+url_z' +\
-      '&per_page={nb_per_page}&format=json&nojsoncallback=1&page={page}'
+url = (
+    'https://api.flickr.com/services/rest/?method=flickr.photos.search'
+    + '&api_key={api_key}&{text}&sort=relevance'
+    + '&extras=description%2C+owner_name%2C+url_o%2C+url_n%2C+url_z'
+    + '&per_page={nb_per_page}&format=json&nojsoncallback=1&page={page}'
+)
 photo_url = 'https://www.flickr.com/photos/{userid}/{photoid}'
 
 paging = True
@@ -39,10 +41,9 @@ def build_flickr_url(user_id, photo_id):
 
 
 def request(query, params):
-    params['url'] = url.format(text=urlencode({'text': query}),
-                               api_key=api_key,
-                               nb_per_page=nb_per_page,
-                               page=params['pageno'])
+    params['url'] = url.format(
+        text=urlencode({'text': query}), api_key=api_key, nb_per_page=nb_per_page, page=params['pageno']
+    )
     return params
 
 
@@ -69,7 +70,7 @@ def response(resp):
         else:
             continue
 
-# For a bigger thumbnail, keep only the url_z, not the url_n
+        # For a bigger thumbnail, keep only the url_z, not the url_n
         if 'url_n' in photo:
             thumbnail_src = photo['url_n']
         elif 'url_z' in photo:
@@ -80,13 +81,17 @@ def response(resp):
         url = build_flickr_url(photo['owner'], photo['id'])
 
         # append result
-        results.append({'url': url,
-                        'title': photo['title'],
-                        'img_src': img_src,
-                        'thumbnail_src': thumbnail_src,
-                        'content': photo['description']['_content'],
-                        'author': photo['ownername'],
-                        'template': 'images.html'})
+        results.append(
+            {
+                'url': url,
+                'title': photo['title'],
+                'img_src': img_src,
+                'thumbnail_src': thumbnail_src,
+                'content': photo['description']['_content'],
+                'author': photo['ownername'],
+                'template': 'images.html',
+            }
+        )
 
     # return results
     return results
diff --git a/searx/engines/flickr_noapi.py b/searx/engines/flickr_noapi.py
index 1d670ee50..4ff59fc52 100644
--- a/searx/engines/flickr_noapi.py
+++ b/searx/engines/flickr_noapi.py
@@ -30,10 +30,12 @@ image_sizes = ('o', 'k', 'h', 'b', 'c', 'z', 'n', 'm', 't', 'q', 's')
 
 paging = True
 time_range_support = True
-time_range_dict = {'day': 60 * 60 * 24,
-                   'week': 60 * 60 * 24 * 7,
-                   'month': 60 * 60 * 24 * 7 * 4,
-                   'year': 60 * 60 * 24 * 7 * 52}
+time_range_dict = {
+    'day': 60 * 60 * 24,
+    'week': 60 * 60 * 24 * 7,
+    'month': 60 * 60 * 24 * 7 * 4,
+    'year': 60 * 60 * 24 * 7 * 52,
+}
 
 
 def build_flickr_url(user_id, photo_id):
@@ -47,8 +49,9 @@ def _get_time_range_url(time_range):
 
 
 def request(query, params):
-    params['url'] = (search_url.format(query=urlencode({'text': query}), page=params['pageno'])
-                     + _get_time_range_url(params['time_range']))
+    params['url'] = search_url.format(query=urlencode({'text': query}), page=params['pageno']) + _get_time_range_url(
+        params['time_range']
+    )
     return params
 
 
@@ -83,10 +86,9 @@ def response(resp):
         for image_size in image_sizes:
             if image_size in photo['sizes']:
                 img_src = photo['sizes'][image_size]['url']
-                img_format = 'jpg ' \
-                    + str(photo['sizes'][image_size]['width']) \
-                    + 'x' \
-                    + str(photo['sizes'][image_size]['height'])
+                img_format = (
+                    'jpg ' + str(photo['sizes'][image_size]['width']) + 'x' + str(photo['sizes'][image_size]['height'])
+                )
                 break
 
         if not img_src:
@@ -113,7 +115,7 @@ def response(resp):
             'thumbnail_src': thumbnail_src,
             'source': source,
             'img_format': img_format,
-            'template': 'images.html'
+            'template': 'images.html',
         }
         result['author'] = author.encode(errors='ignore').decode()
         result['source'] = source.encode(errors='ignore').decode()
diff --git a/searx/engines/framalibre.py b/searx/engines/framalibre.py
index 42c08cf95..b2c9d9077 100644
--- a/searx/engines/framalibre.py
+++ b/searx/engines/framalibre.py
@@ -35,9 +35,8 @@ content_xpath = './/div[@class="content"]//p'
 
 # do search-request
 def request(query, params):
-    offset = (params['pageno'] - 1)
-    params['url'] = search_url.format(query=urlencode({'keys': query}),
-                                      offset=offset)
+    offset = params['pageno'] - 1
+    params['url'] = search_url.format(query=urlencode({'keys': query}), offset=offset)
 
     return params
 
@@ -63,10 +62,7 @@ def response(resp):
         content = escape(extract_text(result.xpath(content_xpath)))
 
         # append result
-        results.append({'url': href,
-                        'title': title,
-                        'img_src': thumbnail,
-                        'content': content})
+        results.append({'url': href, 'title': title, 'img_src': thumbnail, 'content': content})
 
     # return results
     return results
diff --git a/searx/engines/freesound.py b/searx/engines/freesound.py
index d2564946c..121a6a5b0 100644
--- a/searx/engines/freesound.py
+++ b/searx/engines/freesound.py
@@ -26,8 +26,7 @@ paging = True
 # search url
 url = "https://freesound.org/apiv2/"
 search_url = (
-    url
-    + "search/text/?query={query}&page={page}&fields=name,url,download,created,description,type&token={api_key}"
+    url + "search/text/?query={query}&page={page}&fields=name,url,download,created,description,type&token={api_key}"
 )
 
 embedded_url = '<audio controls><source src="{uri}" type="audio/{ftype}"></audio>'
diff --git a/searx/engines/frinkiac.py b/searx/engines/frinkiac.py
index f43bb6e20..95a1366de 100644
--- a/searx/engines/frinkiac.py
+++ b/searx/engines/frinkiac.py
@@ -10,10 +10,7 @@ from urllib.parse import urlencode
 about = {
     "website": 'https://frinkiac.com',
     "wikidata_id": 'Q24882614',
-    "official_api_documentation": {
-        'url': None,
-        'comment': 'see https://github.com/MitchellAW/CompuGlobal'
-    },
+    "official_api_documentation": {'url': None, 'comment': 'see https://github.com/MitchellAW/CompuGlobal'},
     "use_official_api": False,
     "require_api_key": False,
     "results": 'JSON',
@@ -40,12 +37,15 @@ def response(resp):
         episode = result['Episode']
         timestamp = result['Timestamp']
 
-        results.append({'template': 'images.html',
-                        'url': RESULT_URL.format(base=BASE,
-                                                 query=urlencode({'p': 'caption', 'e': episode, 't': timestamp})),
-                        'title': episode,
-                        'content': '',
-                        'thumbnail_src': THUMB_URL.format(base=BASE, episode=episode, timestamp=timestamp),
-                        'img_src': IMAGE_URL.format(base=BASE, episode=episode, timestamp=timestamp)})
+        results.append(
+            {
+                'template': 'images.html',
+                'url': RESULT_URL.format(base=BASE, query=urlencode({'p': 'caption', 'e': episode, 't': timestamp})),
+                'title': episode,
+                'content': '',
+                'thumbnail_src': THUMB_URL.format(base=BASE, episode=episode, timestamp=timestamp),
+                'img_src': IMAGE_URL.format(base=BASE, episode=episode, timestamp=timestamp),
+            }
+        )
 
     return results
diff --git a/searx/engines/gentoo.py b/searx/engines/gentoo.py
index 325e132a6..5b9edafe0 100644
--- a/searx/engines/gentoo.py
+++ b/searx/engines/gentoo.py
@@ -37,15 +37,12 @@ def locale_to_lang_code(locale):
 # wikis for some languages were moved off from the main site, we need to make
 # requests to correct URLs to be able to get results in those languages
 lang_urls = {
-    'en': {
-        'base': 'https://wiki.gentoo.org',
-        'search': '/index.php?title=Special:Search&offset={offset}&{query}'
-    },
+    'en': {'base': 'https://wiki.gentoo.org', 'search': '/index.php?title=Special:Search&offset={offset}&{query}'},
     'others': {
         'base': 'https://wiki.gentoo.org',
         'search': '/index.php?title=Special:Search&offset={offset}&{query}\
-                &profile=translation&languagefilter={language}'
-    }
+                &profile=translation&languagefilter={language}',
+    },
 }
 
 
@@ -78,7 +75,7 @@ main_langs = {
     'sl': 'Slovenský',
     'th': 'ไทย',
     'uk': 'Українська',
-    'zh': '简体中文'
+    'zh': '简体中文',
 }
 supported_languages = dict(lang_urls, **main_langs)
 
@@ -101,8 +98,7 @@ def request(query, params):
     urls = get_lang_urls(language)
     search_url = urls['base'] + urls['search']
 
-    params['url'] = search_url.format(query=query, offset=offset,
-                                      language=language)
+    params['url'] = search_url.format(query=query, offset=offset, language=language)
 
     return params
 
@@ -123,7 +119,6 @@ def response(resp):
         href = urljoin(base_url, link.attrib.get('href'))
         title = extract_text(link)
 
-        results.append({'url': href,
-                        'title': title})
+        results.append({'url': href, 'title': title})
 
     return results
diff --git a/searx/engines/gigablast.py b/searx/engines/gigablast.py
index 0f685abc5..c657dca30 100644
--- a/searx/engines/gigablast.py
+++ b/searx/engines/gigablast.py
@@ -55,12 +55,12 @@ def fetch_extra_param(query_args, headers):
     extra_param_path = search_path + urlencode(query_args)
     text = get(base_url + extra_param_path, headers=headers).text
 
-    re_var= None
+    re_var = None
     for line in text.splitlines():
         if re_var is None and extra_param_path in line:
             var = line.split("=")[0].split()[1]  # e.g. var --> 'uxrl'
             re_var = re.compile(var + "\\s*=\\s*" + var + "\\s*\\+\\s*'" + "(.*)" + "'(.*)")
-            extra_param = line.split("'")[1][len(extra_param_path):]
+            extra_param = line.split("'")[1][len(extra_param_path) :]
             continue
         if re_var is not None and re_var.search(line):
             extra_param += re_var.search(line).group(1)
@@ -69,12 +69,7 @@ def fetch_extra_param(query_args, headers):
 
 # do search-request
 def request(query, params):  # pylint: disable=unused-argument
-    query_args = dict(
-        c = 'main'
-        , q = query
-        , dr = 1
-        , showgoodimages = 0
-    )
+    query_args = dict(c='main', q=query, dr=1, showgoodimages=0)
 
     if params['language'] and params['language'] != 'all':
         query_args['qlangcountry'] = params['language']
@@ -93,6 +88,7 @@ def request(query, params):  # pylint: disable=unused-argument
 
     return params
 
+
 # get response from search-request
 def response(resp):
     results = []
@@ -125,10 +121,6 @@ def response(resp):
         if len(subtitle) > 3 and subtitle != title:
             title += " - " + subtitle
 
-        results.append(dict(
-            url = url
-            , title = title
-            , content = content
-        ))
+        results.append(dict(url=url, title=title, content=content))
 
     return results
diff --git a/searx/engines/github.py b/searx/engines/github.py
index b68caa350..1d12d296a 100644
--- a/searx/engines/github.py
+++ b/searx/engines/github.py
@@ -55,9 +55,7 @@ def response(resp):
             content = ''
 
         # append result
-        results.append({'url': url,
-                        'title': title,
-                        'content': content})
+        results.append({'url': url, 'title': title, 'content': content})
 
     # return results
     return results
diff --git a/searx/engines/google.py b/searx/engines/google.py
index 578dec60c..685697d29 100644
--- a/searx/engines/google.py
+++ b/searx/engines/google.py
@@ -50,72 +50,63 @@ supported_languages_url = 'https://www.google.com/preferences?#languages'
 
 # based on https://en.wikipedia.org/wiki/List_of_Google_domains and tests
 google_domains = {
-    'BG': 'google.bg',      # Bulgaria
-    'CZ': 'google.cz',      # Czech Republic
-    'DE': 'google.de',      # Germany
-    'DK': 'google.dk',      # Denmark
-    'AT': 'google.at',      # Austria
-    'CH': 'google.ch',      # Switzerland
-    'GR': 'google.gr',      # Greece
+    'BG': 'google.bg',  # Bulgaria
+    'CZ': 'google.cz',  # Czech Republic
+    'DE': 'google.de',  # Germany
+    'DK': 'google.dk',  # Denmark
+    'AT': 'google.at',  # Austria
+    'CH': 'google.ch',  # Switzerland
+    'GR': 'google.gr',  # Greece
     'AU': 'google.com.au',  # Australia
-    'CA': 'google.ca',      # Canada
-    'GB': 'google.co.uk',   # United Kingdom
-    'ID': 'google.co.id',   # Indonesia
-    'IE': 'google.ie',      # Ireland
-    'IN': 'google.co.in',   # India
+    'CA': 'google.ca',  # Canada
+    'GB': 'google.co.uk',  # United Kingdom
+    'ID': 'google.co.id',  # Indonesia
+    'IE': 'google.ie',  # Ireland
+    'IN': 'google.co.in',  # India
     'MY': 'google.com.my',  # Malaysia
-    'NZ': 'google.co.nz',   # New Zealand
+    'NZ': 'google.co.nz',  # New Zealand
     'PH': 'google.com.ph',  # Philippines
     'SG': 'google.com.sg',  # Singapore
-    'US': 'google.com',     # United States (google.us) redirects to .com
-    'ZA': 'google.co.za',   # South Africa
+    'US': 'google.com',  # United States (google.us) redirects to .com
+    'ZA': 'google.co.za',  # South Africa
     'AR': 'google.com.ar',  # Argentina
-    'CL': 'google.cl',      # Chile
-    'ES': 'google.es',      # Spain
+    'CL': 'google.cl',  # Chile
+    'ES': 'google.es',  # Spain
     'MX': 'google.com.mx',  # Mexico
-    'EE': 'google.ee',      # Estonia
-    'FI': 'google.fi',      # Finland
-    'BE': 'google.be',      # Belgium
-    'FR': 'google.fr',      # France
-    'IL': 'google.co.il',   # Israel
-    'HR': 'google.hr',      # Croatia
-    'HU': 'google.hu',      # Hungary
-    'IT': 'google.it',      # Italy
-    'JP': 'google.co.jp',   # Japan
-    'KR': 'google.co.kr',   # South Korea
-    'LT': 'google.lt',      # Lithuania
-    'LV': 'google.lv',      # Latvia
-    'NO': 'google.no',      # Norway
-    'NL': 'google.nl',      # Netherlands
-    'PL': 'google.pl',      # Poland
+    'EE': 'google.ee',  # Estonia
+    'FI': 'google.fi',  # Finland
+    'BE': 'google.be',  # Belgium
+    'FR': 'google.fr',  # France
+    'IL': 'google.co.il',  # Israel
+    'HR': 'google.hr',  # Croatia
+    'HU': 'google.hu',  # Hungary
+    'IT': 'google.it',  # Italy
+    'JP': 'google.co.jp',  # Japan
+    'KR': 'google.co.kr',  # South Korea
+    'LT': 'google.lt',  # Lithuania
+    'LV': 'google.lv',  # Latvia
+    'NO': 'google.no',  # Norway
+    'NL': 'google.nl',  # Netherlands
+    'PL': 'google.pl',  # Poland
     'BR': 'google.com.br',  # Brazil
-    'PT': 'google.pt',      # Portugal
-    'RO': 'google.ro',      # Romania
-    'RU': 'google.ru',      # Russia
-    'SK': 'google.sk',      # Slovakia
-    'SI': 'google.si',      # Slovenia
-    'SE': 'google.se',      # Sweden
-    'TH': 'google.co.th',   # Thailand
+    'PT': 'google.pt',  # Portugal
+    'RO': 'google.ro',  # Romania
+    'RU': 'google.ru',  # Russia
+    'SK': 'google.sk',  # Slovakia
+    'SI': 'google.si',  # Slovenia
+    'SE': 'google.se',  # Sweden
+    'TH': 'google.co.th',  # Thailand
     'TR': 'google.com.tr',  # Turkey
     'UA': 'google.com.ua',  # Ukraine
     'CN': 'google.com.hk',  # There is no google.cn, we use .com.hk for zh-CN
     'HK': 'google.com.hk',  # Hong Kong
-    'TW': 'google.com.tw'   # Taiwan
+    'TW': 'google.com.tw',  # Taiwan
 }
 
-time_range_dict = {
-    'day': 'd',
-    'week': 'w',
-    'month': 'm',
-    'year': 'y'
-}
+time_range_dict = {'day': 'd', 'week': 'w', 'month': 'm', 'year': 'y'}
 
 # Filter results. 0: None, 1: Moderate, 2: Strict
-filter_mapping = {
-    0: 'off',
-    1: 'medium',
-    2: 'high'
-}
+filter_mapping = {0: 'off', 1: 'medium', 2: 'high'}
 
 # specific xpath variables
 # ------------------------
@@ -140,6 +131,7 @@ content_xpath = './/div[@class="IsZvec"]'
 # from the links not the links itself.
 suggestion_xpath = '//div[contains(@class, "EIaa9b")]//a'
 
+
 def get_lang_info(params, lang_list, custom_aliases, supported_any_language):
     """Composing various language properties for the google engines.
 
@@ -184,11 +176,11 @@ def get_lang_info(params, lang_list, custom_aliases, supported_any_language):
             request's headers)
     """
     ret_val = {
-        'language' : None,
-        'country' : None,
-        'subdomain' : None,
-        'params' : {},
-        'headers' : {},
+        'language': None,
+        'country': None,
+        'subdomain': None,
+        'params': {},
+        'headers': {},
     }
 
     # language ...
@@ -213,7 +205,7 @@ def get_lang_info(params, lang_list, custom_aliases, supported_any_language):
 
     # subdomain ...
 
-    ret_val['subdomain']  = 'www.' + google_domains.get(country.upper(), 'google.com')
+    ret_val['subdomain'] = 'www.' + google_domains.get(country.upper(), 'google.com')
 
     # params & headers
 
@@ -250,15 +242,18 @@ def get_lang_info(params, lang_list, custom_aliases, supported_any_language):
         ret_val['params']['lr'] = "lang_" + lang_list.get(lang_country, language)
 
         # Accept-Language: fr-CH, fr;q=0.8, en;q=0.6, *;q=0.5
-        ret_val['headers']['Accept-Language'] = ','.join([
-            lang_country,
-            language + ';q=0.8,',
-            'en;q=0.6',
-            '*;q=0.5',
-        ])
+        ret_val['headers']['Accept-Language'] = ','.join(
+            [
+                lang_country,
+                language + ';q=0.8,',
+                'en;q=0.6',
+                '*;q=0.5',
+            ]
+        )
 
     return ret_val
 
+
 def detect_google_sorry(resp):
     if resp.url.host == 'sorry.google.com' or resp.url.path.startswith('/sorry'):
         raise SearxEngineCaptchaException()
@@ -269,9 +264,7 @@ def request(query, params):
 
     offset = (params['pageno'] - 1) * 10
 
-    lang_info = get_lang_info(
-        params, supported_languages, language_aliases, True
-    )
+    lang_info = get_lang_info(params, supported_languages, language_aliases, True)
 
     additional_parameters = {}
     if use_mobile_ui:
@@ -281,15 +274,23 @@ def request(query, params):
         }
 
     # https://www.google.de/search?q=corona&hl=de&lr=lang_de&start=0&tbs=qdr%3Ad&safe=medium
-    query_url = 'https://' + lang_info['subdomain'] + '/search' + "?" + urlencode({
-        'q': query,
-        **lang_info['params'],
-        'ie': "utf8",
-        'oe': "utf8",
-        'start': offset,
-        'filter': '0',
-        **additional_parameters,
-    })
+    query_url = (
+        'https://'
+        + lang_info['subdomain']
+        + '/search'
+        + "?"
+        + urlencode(
+            {
+                'q': query,
+                **lang_info['params'],
+                'ie': "utf8",
+                'oe': "utf8",
+                'start': offset,
+                'filter': '0',
+                **additional_parameters,
+            }
+        )
+    )
 
     if params['time_range'] in time_range_dict:
         query_url += '&' + urlencode({'tbs': 'qdr:' + time_range_dict[params['time_range']]})
@@ -301,9 +302,7 @@ def request(query, params):
     if use_mobile_ui:
         params['headers']['Accept'] = '*/*'
     else:
-        params['headers']['Accept'] = (
-            'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'
-        )
+        params['headers']['Accept'] = 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'
 
     return params
 
@@ -325,7 +324,7 @@ def response(resp):
     else:
         logger.debug("did not find 'answer'")
 
-    # results --> number_of_results
+        # results --> number_of_results
         if not use_mobile_ui:
             try:
                 _txt = eval_xpath_getindex(dom, '//div[@id="result-stats"]//text()', 0)
@@ -355,11 +354,7 @@ def response(resp):
             if url is None:
                 continue
             content = extract_text(eval_xpath_getindex(result, content_xpath, 0, default=None), allow_none=True)
-            results.append({
-                'url': url,
-                'title': title,
-                'content': content
-            })
+            results.append({'url': url, 'title': title, 'content': content})
         except Exception as e:  # pylint: disable=broad-except
             logger.error(e, exc_info=True)
             # from lxml import etree
diff --git a/searx/engines/google_images.py b/searx/engines/google_images.py
index 61d291e3f..203df404a 100644
--- a/searx/engines/google_images.py
+++ b/searx/engines/google_images.py
@@ -30,10 +30,8 @@ from searx.engines.google import (
 )
 
 # pylint: disable=unused-import
-from searx.engines.google import (
-    supported_languages_url
-    ,  _fetch_supported_languages
-)
+from searx.engines.google import supported_languages_url, _fetch_supported_languages
+
 # pylint: enable=unused-import
 
 # about
@@ -53,21 +51,16 @@ use_locale_domain = True
 time_range_support = True
 safesearch = True
 
-filter_mapping = {
-    0: 'images',
-    1: 'active',
-    2: 'active'
-}
+filter_mapping = {0: 'images', 1: 'active', 2: 'active'}
 
 
 def scrap_out_thumbs(dom):
-    """Scrap out thumbnail data from <script> tags.
-    """
+    """Scrap out thumbnail data from <script> tags."""
     ret_val = {}
     for script in eval_xpath(dom, '//script[contains(., "_setImgSrc(")]'):
         _script = script.text
         # _setImgSrc('0','data:image\/jpeg;base64,\/9j\/4AAQSkZJR ....');
-        _thumb_no, _img_data = _script[len("_setImgSrc("):-2].split(",", 1)
+        _thumb_no, _img_data = _script[len("_setImgSrc(") : -2].split(",", 1)
         _thumb_no = _thumb_no.replace("'", "")
         _img_data = _img_data.replace("'", "")
         _img_data = _img_data.replace(r"\/", r"/")
@@ -76,8 +69,7 @@ def scrap_out_thumbs(dom):
 
 
 def scrap_img_by_id(script, data_id):
-    """Get full image URL by data-id in parent element
-    """
+    """Get full image URL by data-id in parent element"""
     img_url = ''
     _script = script.split('\n')
     for i, line in enumerate(_script):
@@ -91,20 +83,25 @@ def scrap_img_by_id(script, data_id):
 def request(query, params):
     """Google-Video search request"""
 
-    lang_info = get_lang_info(
-        params, supported_languages, language_aliases, False
+    lang_info = get_lang_info(params, supported_languages, language_aliases, False)
+    logger.debug("HTTP header Accept-Language --> %s", lang_info['headers']['Accept-Language'])
+
+    query_url = (
+        'https://'
+        + lang_info['subdomain']
+        + '/search'
+        + "?"
+        + urlencode(
+            {
+                'q': query,
+                'tbm': "isch",
+                **lang_info['params'],
+                'ie': "utf8",
+                'oe': "utf8",
+                'num': 30,
+            }
+        )
     )
-    logger.debug(
-        "HTTP header Accept-Language --> %s", lang_info['headers']['Accept-Language'])
-
-    query_url = 'https://' + lang_info['subdomain'] + '/search' + "?" + urlencode({
-        'q': query,
-        'tbm': "isch",
-        **lang_info['params'],
-        'ie': "utf8",
-        'oe': "utf8",
-        'num': 30,
-    })
 
     if params['time_range'] in time_range_dict:
         query_url += '&' + urlencode({'tbs': 'qdr:' + time_range_dict[params['time_range']]})
@@ -113,9 +110,7 @@ def request(query, params):
     params['url'] = query_url
 
     params['headers'].update(lang_info['headers'])
-    params['headers']['Accept'] = (
-        'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'
-    )
+    params['headers']['Accept'] = 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'
     return params
 
 
@@ -128,8 +123,7 @@ def response(resp):
     # convert the text to dom
     dom = html.fromstring(resp.text)
     img_bas64_map = scrap_out_thumbs(dom)
-    img_src_script = eval_xpath_getindex(
-        dom, '//script[contains(., "AF_initDataCallback({key: ")]', 1).text
+    img_src_script = eval_xpath_getindex(dom, '//script[contains(., "AF_initDataCallback({key: ")]', 1).text
 
     # parse results
     #
@@ -189,15 +183,17 @@ def response(resp):
         if not src_url:
             src_url = thumbnail_src
 
-        results.append({
-            'url': url,
-            'title': img_alt,
-            'content': pub_descr,
-            'source': pub_source,
-            'img_src': src_url,
-            # 'img_format': img_format,
-            'thumbnail_src': thumbnail_src,
-            'template': 'images.html'
-        })
+        results.append(
+            {
+                'url': url,
+                'title': img_alt,
+                'content': pub_descr,
+                'source': pub_source,
+                'img_src': src_url,
+                # 'img_format': img_format,
+                'thumbnail_src': thumbnail_src,
+                'template': 'images.html',
+            }
+        )
 
     return results
diff --git a/searx/engines/google_news.py b/searx/engines/google_news.py
index 87ac9a19d..162e4348e 100644
--- a/searx/engines/google_news.py
+++ b/searx/engines/google_news.py
@@ -32,6 +32,7 @@ from searx.engines.google import (
     supported_languages_url,
     _fetch_supported_languages,
 )
+
 # pylint: enable=unused-import
 
 from searx.engines.google import (
@@ -71,14 +72,12 @@ time_range_support = True
 #  safesearch : results are identitical for safesearch=0 and safesearch=2
 safesearch = False
 
+
 def request(query, params):
     """Google-News search request"""
 
-    lang_info = get_lang_info(
-        params, supported_languages, language_aliases, False
-    )
-    logger.debug(
-        "HTTP header Accept-Language --> %s", lang_info['headers']['Accept-Language'])
+    lang_info = get_lang_info(params, supported_languages, language_aliases, False)
+    logger.debug("HTTP header Accept-Language --> %s", lang_info['headers']['Accept-Language'])
 
     # google news has only one domain
     lang_info['subdomain'] = 'news.google.com'
@@ -94,19 +93,26 @@ def request(query, params):
     if params['time_range']:
         query += ' ' + time_range_dict[params['time_range']]
 
-    query_url = 'https://' + lang_info['subdomain'] + '/search' + "?" + urlencode({
-        'q': query,
-        **lang_info['params'],
-        'ie': "utf8",
-        'oe': "utf8",
-        'gl': lang_info['country'],
-    }) + ('&ceid=%s' % ceid)  # ceid includes a ':' character which must not be urlencoded
+    query_url = (
+        'https://'
+        + lang_info['subdomain']
+        + '/search'
+        + "?"
+        + urlencode(
+            {
+                'q': query,
+                **lang_info['params'],
+                'ie': "utf8",
+                'oe': "utf8",
+                'gl': lang_info['country'],
+            }
+        )
+        + ('&ceid=%s' % ceid)
+    )  # ceid includes a ':' character which must not be urlencoded
     params['url'] = query_url
 
     params['headers'].update(lang_info['headers'])
-    params['headers']['Accept'] = (
-        'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'
-        )
+    params['headers']['Accept'] = 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'
     params['headers']['Cookie'] = "CONSENT=YES+cb.%s-14-p0.en+F+941;" % datetime.now().strftime("%Y%m%d")
 
     return params
@@ -141,7 +147,7 @@ def response(resp):
             # jslog="95014; 5:W251bGwsbnVsbCxudW...giXQ==; track:click"
             jslog = jslog.split(";")[1].split(':')[1].strip()
             try:
-                padding = (4 -(len(jslog) % 4)) * "="
+                padding = (4 - (len(jslog) % 4)) * "="
                 jslog = b64decode(jslog + padding)
             except binascii.Error:
                 # URL cant be read, skip this result
@@ -178,12 +184,14 @@ def response(resp):
 
         img_src = extract_text(result.xpath('preceding-sibling::a/figure/img/@src'))
 
-        results.append({
-            'url':      url,
-            'title':    title,
-            'content':  content,
-            'img_src':  img_src,
-        })
+        results.append(
+            {
+                'url': url,
+                'title': title,
+                'content': content,
+                'img_src': img_src,
+            }
+        )
 
     # return results
     return results
diff --git a/searx/engines/google_scholar.py b/searx/engines/google_scholar.py
index e6726463d..e0700957c 100644
--- a/searx/engines/google_scholar.py
+++ b/searx/engines/google_scholar.py
@@ -32,6 +32,7 @@ from searx.engines.google import (
     supported_languages_url,
     _fetch_supported_languages,
 )
+
 # pylint: enable=unused-import
 
 # about
@@ -52,6 +53,7 @@ use_locale_domain = True
 time_range_support = True
 safesearch = False
 
+
 def time_range_url(params):
     """Returns a URL query component for a google-Scholar time range based on
     ``params['time_range']``.  Google-Scholar does only support ranges in years.
@@ -64,7 +66,7 @@ def time_range_url(params):
     # as_ylo=2016&as_yhi=2019
     ret_val = ''
     if params['time_range'] in time_range_dict:
-        ret_val= urlencode({'as_ylo': datetime.now().year -1 })
+        ret_val = urlencode({'as_ylo': datetime.now().year - 1})
     return '&' + ret_val
 
 
@@ -72,34 +74,38 @@ def request(query, params):
     """Google-Scholar search request"""
 
     offset = (params['pageno'] - 1) * 10
-    lang_info = get_lang_info(
-        params, supported_languages, language_aliases, False
-    )
-    logger.debug(
-        "HTTP header Accept-Language --> %s", lang_info['headers']['Accept-Language'])
+    lang_info = get_lang_info(params, supported_languages, language_aliases, False)
+    logger.debug("HTTP header Accept-Language --> %s", lang_info['headers']['Accept-Language'])
 
     # subdomain is: scholar.google.xy
     lang_info['subdomain'] = lang_info['subdomain'].replace("www.", "scholar.")
 
-    query_url = 'https://'+ lang_info['subdomain'] + '/scholar' + "?" + urlencode({
-        'q':  query,
-        **lang_info['params'],
-        'ie': "utf8",
-        'oe':  "utf8",
-        'start' : offset,
-    })
+    query_url = (
+        'https://'
+        + lang_info['subdomain']
+        + '/scholar'
+        + "?"
+        + urlencode(
+            {
+                'q': query,
+                **lang_info['params'],
+                'ie': "utf8",
+                'oe': "utf8",
+                'start': offset,
+            }
+        )
+    )
 
     query_url += time_range_url(params)
     params['url'] = query_url
 
     params['headers'].update(lang_info['headers'])
-    params['headers']['Accept'] = (
-        'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'
-    )
+    params['headers']['Accept'] = 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'
 
-    #params['google_subdomain'] = subdomain
+    # params['google_subdomain'] = subdomain
     return params
 
+
 def response(resp):
     """Get response from google's search request"""
     results = []
@@ -132,11 +138,13 @@ def response(resp):
         if pub_type:
             title = title + " " + pub_type
 
-        results.append({
-            'url':      url,
-            'title':    title,
-            'content':  content,
-        })
+        results.append(
+            {
+                'url': url,
+                'title': title,
+                'content': content,
+            }
+        )
 
     # parse suggestion
     for suggestion in eval_xpath(dom, '//div[contains(@class, "gs_qsuggest_wrap")]//li//a'):
diff --git a/searx/engines/google_videos.py b/searx/engines/google_videos.py
index 77b0ab260..049f9138c 100644
--- a/searx/engines/google_videos.py
+++ b/searx/engines/google_videos.py
@@ -38,10 +38,8 @@ from searx.engines.google import (
 )
 
 # pylint: disable=unused-import
-from searx.engines.google import (
-    supported_languages_url
-    ,  _fetch_supported_languages
-)
+from searx.engines.google import supported_languages_url, _fetch_supported_languages
+
 # pylint: enable=unused-import
 
 # about
@@ -65,6 +63,7 @@ safesearch = True
 
 RE_CACHE = {}
 
+
 def _re(regexpr):
     """returns compiled regular expression"""
     RE_CACHE[regexpr] = RE_CACHE.get(regexpr, re.compile(regexpr))
@@ -77,18 +76,17 @@ def scrap_out_thumbs_src(dom):
     for script in eval_xpath_list(dom, '//script[contains(., "google.ldi={")]'):
         _script = script.text
         # "dimg_35":"https://i.ytimg.c....",
-        _dimurl = _re("s='([^']*)").findall( _script)
-        for k,v in _re('(' + thumb_name + '[0-9]*)":"(http[^"]*)' ).findall(_script):
-            v = v.replace(r'\u003d','=')
-            v = v.replace(r'\u0026','&')
+        _dimurl = _re("s='([^']*)").findall(_script)
+        for k, v in _re('(' + thumb_name + '[0-9]*)":"(http[^"]*)').findall(_script):
+            v = v.replace(r'\u003d', '=')
+            v = v.replace(r'\u0026', '&')
             ret_val[k] = v
     logger.debug("found %s imgdata for: %s", thumb_name, ret_val.keys())
     return ret_val
 
 
 def scrap_out_thumbs(dom):
-    """Scrap out thumbnail data from <script> tags.
-    """
+    """Scrap out thumbnail data from <script> tags."""
     ret_val = {}
     thumb_name = 'dimg_'
 
@@ -96,7 +94,7 @@ def scrap_out_thumbs(dom):
         _script = script.text
 
         # var s='data:image/jpeg;base64, ...'
-        _imgdata = _re("s='([^']*)").findall( _script)
+        _imgdata = _re("s='([^']*)").findall(_script)
         if not _imgdata:
             continue
 
@@ -112,19 +110,24 @@ def scrap_out_thumbs(dom):
 def request(query, params):
     """Google-Video search request"""
 
-    lang_info = get_lang_info(
-        params, supported_languages, language_aliases, False
+    lang_info = get_lang_info(params, supported_languages, language_aliases, False)
+    logger.debug("HTTP header Accept-Language --> %s", lang_info['headers']['Accept-Language'])
+
+    query_url = (
+        'https://'
+        + lang_info['subdomain']
+        + '/search'
+        + "?"
+        + urlencode(
+            {
+                'q': query,
+                'tbm': "vid",
+                **lang_info['params'],
+                'ie': "utf8",
+                'oe': "utf8",
+            }
+        )
     )
-    logger.debug(
-        "HTTP header Accept-Language --> %s", lang_info['headers']['Accept-Language'])
-
-    query_url = 'https://' + lang_info['subdomain'] + '/search' + "?" + urlencode({
-        'q':   query,
-        'tbm': "vid",
-        **lang_info['params'],
-        'ie': "utf8",
-        'oe': "utf8",
-    })
 
     if params['time_range'] in time_range_dict:
         query_url += '&' + urlencode({'tbs': 'qdr:' + time_range_dict[params['time_range']]})
@@ -133,9 +136,7 @@ def request(query, params):
     params['url'] = query_url
 
     params['headers'].update(lang_info['headers'])
-    params['headers']['Accept'] = (
-        'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'
-        )
+    params['headers']['Accept'] = 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'
     return params
 
 
@@ -171,21 +172,22 @@ def response(resp):
 
         title = extract_text(eval_xpath_getindex(result, title_xpath, 0))
         url = eval_xpath_getindex(result, './/div[@class="dXiKIc"]//a/@href', 0)
-        length = extract_text(eval_xpath(
-            result, './/div[contains(@class, "P7xzyf")]/span/span'))
+        length = extract_text(eval_xpath(result, './/div[contains(@class, "P7xzyf")]/span/span'))
         c_node = eval_xpath_getindex(result, './/div[@class="Uroaid"]', 0)
         content = extract_text(c_node)
         pub_info = extract_text(eval_xpath(result, './/div[@class="Zg1NU"]'))
 
-        results.append({
-            'url':         url,
-            'title':       title,
-            'content':     content,
-            'length':      length,
-            'author':      pub_info,
-            'thumbnail':   img_src,
-            'template':    'videos.html',
-            })
+        results.append(
+            {
+                'url': url,
+                'title': title,
+                'content': content,
+                'length': length,
+                'author': pub_info,
+                'thumbnail': img_src,
+                'template': 'videos.html',
+            }
+        )
 
     # parse suggestion
     for suggestion in eval_xpath_list(dom, suggestion_xpath):
diff --git a/searx/engines/imdb.py b/searx/engines/imdb.py
index a7474fd5b..bb6258cf4 100644
--- a/searx/engines/imdb.py
+++ b/searx/engines/imdb.py
@@ -27,7 +27,9 @@ about = {
     "results": 'HTML',
 }
 
-categories = ['general', ]
+categories = [
+    'general',
+]
 paging = False
 
 # suggestion_url = "https://sg.media-imdb.com/suggestion/{letter}/{query}.json"
@@ -35,13 +37,7 @@ suggestion_url = "https://v2.sg.media-imdb.com/suggestion/{letter}/{query}.json"
 
 href_base = 'https://imdb.com/{category}/{entry_id}'
 
-search_categories = {
-    "nm": "name",
-    "tt": "title",
-    "kw": "keyword",
-    "co": "company",
-    "ep": "episode"
-}
+search_categories = {"nm": "name", "tt": "title", "kw": "keyword", "co": "company", "ep": "episode"}
 
 
 def request(query, params):
@@ -63,9 +59,7 @@ def response(resp):
         entry_id = entry['id']
         categ = search_categories.get(entry_id[:2])
         if categ is None:
-            logger.error(
-                'skip unknown category tag %s in %s', entry_id[:2], entry_id
-            )
+            logger.error('skip unknown category tag %s in %s', entry_id[:2], entry_id)
             continue
 
         title = entry['l']
@@ -95,11 +89,13 @@ def response(resp):
             if not image_url_name.endswith('_V1_'):
                 magic = '_V1_' + magic
             image_url = image_url_name + magic + '.' + image_url_prefix
-        results.append({
-            "title":  title,
-            "url": href_base.format(category=categ, entry_id=entry_id),
-            "content": content,
-            "img_src" : image_url,
-        })
+        results.append(
+            {
+                "title": title,
+                "url": href_base.format(category=categ, entry_id=entry_id),
+                "content": content,
+                "img_src": image_url,
+            }
+        )
 
     return results
diff --git a/searx/engines/ina.py b/searx/engines/ina.py
index 81172ef8c..1e21bcef8 100644
--- a/searx/engines/ina.py
+++ b/searx/engines/ina.py
@@ -41,9 +41,7 @@ content_xpath = './/p[@class="media-body__summary"]'
 
 # do search-request
 def request(query, params):
-    params['url'] = search_url.format(ps=page_size,
-                                      start=params['pageno'] * page_size,
-                                      query=urlencode({'q': query}))
+    params['url'] = search_url.format(ps=page_size, start=params['pageno'] * page_size, query=urlencode({'q': query}))
 
     return params
 
@@ -75,12 +73,16 @@ def response(resp):
         content = extract_text(result.xpath(content_xpath))
 
         # append result
-        results.append({'url': url,
-                        'title': title,
-                        'content': content,
-                        'template': 'videos.html',
-                        'publishedDate': publishedDate,
-                        'thumbnail': thumbnail})
+        results.append(
+            {
+                'url': url,
+                'title': title,
+                'content': content,
+                'template': 'videos.html',
+                'publishedDate': publishedDate,
+                'thumbnail': thumbnail,
+            }
+        )
 
     # return results
     return results
diff --git a/searx/engines/invidious.py b/searx/engines/invidious.py
index 5d0b00edb..914615d6f 100644
--- a/searx/engines/invidious.py
+++ b/searx/engines/invidious.py
@@ -46,14 +46,10 @@ def request(query, params):
         base_url_rand = base_url
 
     search_url = base_url_rand + "api/v1/search?q={query}"
-    params["url"] = search_url.format(
-        query=quote_plus(query)
-    ) + "&page={pageno}".format(pageno=params["pageno"])
+    params["url"] = search_url.format(query=quote_plus(query)) + "&page={pageno}".format(pageno=params["pageno"])
 
     if params["time_range"] in time_range_dict:
-        params["url"] += "&date={timerange}".format(
-            timerange=time_range_dict[params["time_range"]]
-        )
+        params["url"] += "&date={timerange}".format(timerange=time_range_dict[params["time_range"]])
 
     if params["language"] != "all":
         lang = params["language"].split("-")
@@ -88,17 +84,13 @@ def response(resp):
             url = base_invidious_url + videoid
             embedded = embedded_url.format(videoid=videoid)
             thumbs = result.get("videoThumbnails", [])
-            thumb = next(
-                (th for th in thumbs if th["quality"] == "sddefault"), None
-            )
+            thumb = next((th for th in thumbs if th["quality"] == "sddefault"), None)
             if thumb:
                 thumbnail = thumb.get("url", "")
             else:
                 thumbnail = ""
 
-            publishedDate = parser.parse(
-                time.ctime(result.get("published", 0))
-            )
+            publishedDate = parser.parse(time.ctime(result.get("published", 0)))
             length = time.gmtime(result.get("lengthSeconds"))
             if length.tm_hour:
                 length = time.strftime("%H:%M:%S", length)
diff --git a/searx/engines/json_engine.py b/searx/engines/json_engine.py
index 8a04d34b2..f53bc0bf4 100644
--- a/searx/engines/json_engine.py
+++ b/searx/engines/json_engine.py
@@ -119,22 +119,22 @@ def response(resp):
                 content = query(result, content_query)[0]
             except:
                 content = ""
-            results.append({
-                'url': to_string(url),
-                'title': title_filter(to_string(title)),
-                'content': content_filter(to_string(content)),
-            })
+            results.append(
+                {
+                    'url': to_string(url),
+                    'title': title_filter(to_string(title)),
+                    'content': content_filter(to_string(content)),
+                }
+            )
     else:
-        for url, title, content in zip(
-            query(json, url_query),
-            query(json, title_query),
-            query(json, content_query)
-        ):
-            results.append({
-                'url': to_string(url),
-                'title': title_filter(to_string(title)),
-                'content': content_filter(to_string(content)),
-            })
+        for url, title, content in zip(query(json, url_query), query(json, title_query), query(json, content_query)):
+            results.append(
+                {
+                    'url': to_string(url),
+                    'title': title_filter(to_string(title)),
+                    'content': content_filter(to_string(content)),
+                }
+            )
 
     if not suggestion_query:
         return results
diff --git a/searx/engines/kickass.py b/searx/engines/kickass.py
index ad451dbb1..26364674c 100644
--- a/searx/engines/kickass.py
+++ b/searx/engines/kickass.py
@@ -34,8 +34,7 @@ content_xpath = './/span[@class="font11px lightgrey block"]'
 
 # do search-request
 def request(query, params):
-    params['url'] = search_url.format(search_term=quote(query),
-                                      pageno=params['pageno'])
+    params['url'] = search_url.format(search_term=quote(query), pageno=params['pageno'])
 
     return params
 
@@ -79,16 +78,20 @@ def response(resp):
         torrentfileurl = quote(torrentfile, safe="%/:=&?~#+!$,;'@()*")
 
         # append result
-        results.append({'url': href,
-                        'title': title,
-                        'content': content,
-                        'seed': seed,
-                        'leech': leech,
-                        'filesize': filesize,
-                        'files': files,
-                        'magnetlink': magnetlink,
-                        'torrentfile': torrentfileurl,
-                        'template': 'torrent.html'})
+        results.append(
+            {
+                'url': href,
+                'title': title,
+                'content': content,
+                'seed': seed,
+                'leech': leech,
+                'filesize': filesize,
+                'files': files,
+                'magnetlink': magnetlink,
+                'torrentfile': torrentfileurl,
+                'template': 'torrent.html',
+            }
+        )
 
     # return results sorted by seeder
     return sorted(results, key=itemgetter('seed'), reverse=True)
diff --git a/searx/engines/loc.py b/searx/engines/loc.py
index 5c09ceff2..0b2f3a689 100644
--- a/searx/engines/loc.py
+++ b/searx/engines/loc.py
@@ -34,9 +34,7 @@ IMG_SRC_FIXES = {
 
 def request(query, params):
 
-    search_path = search_string.format(
-        query=urlencode({'q': query}),
-        page=params['pageno'])
+    search_path = search_string.format(query=urlencode({'q': query}), page=params['pageno'])
 
     params['url'] = base_url + search_path
 
@@ -56,13 +54,15 @@ def response(resp):
                 break
         else:
             img_src = result['image']['thumb']
-        results.append({
-            'url': result['links']['item'],
-            'title': result['title'],
-            'img_src': img_src,
-            'thumbnail_src': result['image']['thumb'],
-            'author': result['creator'],
-            'template': 'images.html'
-        })
+        results.append(
+            {
+                'url': result['links']['item'],
+                'title': result['title'],
+                'img_src': img_src,
+                'thumbnail_src': result['image']['thumb'],
+                'author': result['creator'],
+                'template': 'images.html',
+            }
+        )
 
     return results
diff --git a/searx/engines/mediathekviewweb.py b/searx/engines/mediathekviewweb.py
index d4cb853d4..991dcbc7b 100644
--- a/searx/engines/mediathekviewweb.py
+++ b/searx/engines/mediathekviewweb.py
@@ -22,29 +22,33 @@ paging = True
 time_range_support = False
 safesearch = False
 
+
 def request(query, params):
 
     params['url'] = 'https://mediathekviewweb.de/api/query'
     params['method'] = 'POST'
     params['headers']['Content-type'] = 'text/plain'
-    params['data'] = dumps({
-        'queries' : [
-	    {
-	        'fields' : [
-		    'title',
-		    'topic',
-	        ],
-	    'query' : query
-	    },
-        ],
-        'sortBy' : 'timestamp',
-        'sortOrder' : 'desc',
-        'future' : True,
-        'offset' : (params['pageno'] - 1 )* 10,
-        'size' : 10
-    })
+    params['data'] = dumps(
+        {
+            'queries': [
+                {
+                    'fields': [
+                        'title',
+                        'topic',
+                    ],
+                    'query': query,
+                },
+            ],
+            'sortBy': 'timestamp',
+            'sortOrder': 'desc',
+            'future': True,
+            'offset': (params['pageno'] - 1) * 10,
+            'size': 10,
+        }
+    )
     return params
 
+
 def response(resp):
 
     resp = loads(resp.text)
@@ -58,11 +62,13 @@ def response(resp):
 
         item['hms'] = str(datetime.timedelta(seconds=item['duration']))
 
-        results.append({
-            'url' : item['url_video_hd'],
-            'title' : "%(channel)s: %(title)s (%(hms)s)" % item,
-            'length' : item['hms'],
-            'content' : "%(description)s" % item,
-        })
+        results.append(
+            {
+                'url': item['url_video_hd'],
+                'title': "%(channel)s: %(title)s (%(hms)s)" % item,
+                'length': item['hms'],
+                'content': "%(description)s" % item,
+            }
+        )
 
     return results
diff --git a/searx/engines/mediawiki.py b/searx/engines/mediawiki.py
index da4321250..9002e9ba7 100644
--- a/searx/engines/mediawiki.py
+++ b/searx/engines/mediawiki.py
@@ -25,23 +25,24 @@ search_type = 'nearmatch'  # possible values: title, text, nearmatch
 
 # search-url
 base_url = 'https://{language}.wikipedia.org/'
-search_postfix = 'w/api.php?action=query'\
-    '&list=search'\
-    '&{query}'\
-    '&format=json'\
-    '&sroffset={offset}'\
-    '&srlimit={limit}'\
+search_postfix = (
+    'w/api.php?action=query'
+    '&list=search'
+    '&{query}'
+    '&format=json'
+    '&sroffset={offset}'
+    '&srlimit={limit}'
     '&srwhat={searchtype}'
+)
 
 
 # do search-request
 def request(query, params):
     offset = (params['pageno'] - 1) * number_of_results
 
-    string_args = dict(query=urlencode({'srsearch': query}),
-                       offset=offset,
-                       limit=number_of_results,
-                       searchtype=search_type)
+    string_args = dict(
+        query=urlencode({'srsearch': query}), offset=offset, limit=number_of_results, searchtype=search_type
+    )
 
     format_strings = list(Formatter().parse(base_url))
 
@@ -78,13 +79,14 @@ def response(resp):
     for result in search_results['query']['search']:
         if result.get('snippet', '').startswith('#REDIRECT'):
             continue
-        url = base_url.format(language=resp.search_params['language']) +\
-            'wiki/' + quote(result['title'].replace(' ', '_').encode())
+        url = (
+            base_url.format(language=resp.search_params['language'])
+            + 'wiki/'
+            + quote(result['title'].replace(' ', '_').encode())
+        )
 
         # append result
-        results.append({'url': url,
-                        'title': result['title'],
-                        'content': ''})
+        results.append({'url': url, 'title': result['title'], 'content': ''})
 
     # return results
     return results
diff --git a/searx/engines/microsoft_academic.py b/searx/engines/microsoft_academic.py
index c99611049..a869daf2f 100644
--- a/searx/engines/microsoft_academic.py
+++ b/searx/engines/microsoft_academic.py
@@ -26,17 +26,19 @@ def request(query, params):
     params['url'] = search_url
     params['method'] = 'POST'
     params['headers']['content-type'] = 'application/json; charset=utf-8'
-    params['data'] = dumps({
-        'query': query,
-        'queryExpression': '',
-        'filters': [],
-        'orderBy': 0,
-        'skip': (params['pageno'] - 1) * 10,
-        'sortAscending': True,
-        'take': 10,
-        'includeCitationContexts': False,
-        'profileId': '',
-    })
+    params['data'] = dumps(
+        {
+            'query': query,
+            'queryExpression': '',
+            'filters': [],
+            'orderBy': 0,
+            'skip': (params['pageno'] - 1) * 10,
+            'sortAscending': True,
+            'take': 10,
+            'includeCitationContexts': False,
+            'profileId': '',
+        }
+    )
 
     return params
 
@@ -54,11 +56,13 @@ def response(resp):
         title = result['paper']['dn']
         content = _get_content(result['paper'])
         url = _paper_url.format(id=result['paper']['id'])
-        results.append({
-            'url': url,
-            'title': html_to_text(title),
-            'content': html_to_text(content),
-        })
+        results.append(
+            {
+                'url': url,
+                'title': html_to_text(title),
+                'content': html_to_text(content),
+            }
+        )
 
     return results
 
diff --git a/searx/engines/mixcloud.py b/searx/engines/mixcloud.py
index a6fd1c0a1..f5e0f55fc 100644
--- a/searx/engines/mixcloud.py
+++ b/searx/engines/mixcloud.py
@@ -25,16 +25,17 @@ paging = True
 url = 'https://api.mixcloud.com/'
 search_url = url + 'search/?{query}&type=cloudcast&limit=10&offset={offset}'
 
-embedded_url = '<iframe scrolling="no" frameborder="0" allowTransparency="true" ' +\
-    'data-src="https://www.mixcloud.com/widget/iframe/?feed={url}" width="300" height="300"></iframe>'
+embedded_url = (
+    '<iframe scrolling="no" frameborder="0" allowTransparency="true" '
+    + 'data-src="https://www.mixcloud.com/widget/iframe/?feed={url}" width="300" height="300"></iframe>'
+)
 
 
 # do search-request
 def request(query, params):
     offset = (params['pageno'] - 1) * 10
 
-    params['url'] = search_url.format(query=urlencode({'q': query}),
-                                      offset=offset)
+    params['url'] = search_url.format(query=urlencode({'q': query}), offset=offset)
 
     return params
 
@@ -54,11 +55,9 @@ def response(resp):
         publishedDate = parser.parse(result['created_time'])
 
         # append result
-        results.append({'url': url,
-                        'title': title,
-                        'embedded': embedded,
-                        'publishedDate': publishedDate,
-                        'content': content})
+        results.append(
+            {'url': url, 'title': title, 'embedded': embedded, 'publishedDate': publishedDate, 'content': content}
+        )
 
     # return results
     return results
diff --git a/searx/engines/mongodb.py b/searx/engines/mongodb.py
index 2ebb90539..c833ca9e0 100644
--- a/searx/engines/mongodb.py
+++ b/searx/engines/mongodb.py
@@ -26,38 +26,35 @@ result_template = 'key-value.html'
 
 _client = None
 
+
 def init(_):
     connect()
 
+
 def connect():
     global _client  # pylint: disable=global-statement
-    kwargs = { 'port': port }
+    kwargs = {'port': port}
     if username:
         kwargs['username'] = username
     if password:
         kwargs['password'] = password
     _client = MongoClient(host, **kwargs)[database][collection]
 
+
 def search(query, params):
     results = []
     if exact_match_only:
-        q = { '$eq': query }
+        q = {'$eq': query}
     else:
-        _re = re.compile('.*{0}.*'.format(re.escape(query)), re.I | re.M )
-        q = { '$regex': _re }
+        _re = re.compile('.*{0}.*'.format(re.escape(query)), re.I | re.M)
+        q = {'$regex': _re}
 
-    query = _client.find(
-        {key: q}
-    ).skip(
-        ( params['pageno'] -1 ) * results_per_page
-    ).limit(
-        results_per_page
-    )
+    query = _client.find({key: q}).skip((params['pageno'] - 1) * results_per_page).limit(results_per_page)
 
-    results.append({ 'number_of_results': query.count() })
+    results.append({'number_of_results': query.count()})
     for r in query:
         del r['_id']
-        r = { str(k):str(v) for k,v in r.items() }
+        r = {str(k): str(v) for k, v in r.items()}
         r['template'] = result_template
         results.append(r)
 
diff --git a/searx/engines/mysql_server.py b/searx/engines/mysql_server.py
index be89eb86e..d949ee0bc 100644
--- a/searx/engines/mysql_server.py
+++ b/searx/engines/mysql_server.py
@@ -20,6 +20,7 @@ paging = True
 result_template = 'key-value.html'
 _connection = None
 
+
 def init(engine_settings):
     global _connection  # pylint: disable=global-statement
 
@@ -30,13 +31,14 @@ def init(engine_settings):
         raise ValueError('only SELECT query is supported')
 
     _connection = mysql.connector.connect(
-        database = database,
-        user = username,
-        password = password,
-        host = host,
+        database=database,
+        user=username,
+        password=password,
+        host=host,
         auth_plugin=auth_plugin,
     )
 
+
 def search(query, params):
     query_params = {'query': query}
     query_to_run = query_str + ' LIMIT {0} OFFSET {1}'.format(limit, (params['pageno'] - 1) * limit)
@@ -46,6 +48,7 @@ def search(query, params):
 
         return _fetch_results(cur)
 
+
 def _fetch_results(cur):
     results = []
     for res in cur:
diff --git a/searx/engines/nyaa.py b/searx/engines/nyaa.py
index 4fe383efa..bdd3ea6dc 100644
--- a/searx/engines/nyaa.py
+++ b/searx/engines/nyaa.py
@@ -98,14 +98,18 @@ def response(resp):
         content = 'Category: "{category}". Downloaded {downloads} times.'
         content = content.format(category=category, downloads=downloads)
 
-        results.append({'url': href,
-                        'title': title,
-                        'content': content,
-                        'seed': seed,
-                        'leech': leech,
-                        'filesize': filesize,
-                        'torrentfile': torrent_link,
-                        'magnetlink': magnet_link,
-                        'template': 'torrent.html'})
+        results.append(
+            {
+                'url': href,
+                'title': title,
+                'content': content,
+                'seed': seed,
+                'leech': leech,
+                'filesize': filesize,
+                'torrentfile': torrent_link,
+                'magnetlink': magnet_link,
+                'template': 'torrent.html',
+            }
+        )
 
     return results
diff --git a/searx/engines/openstreetmap.py b/searx/engines/openstreetmap.py
index c6211a004..946869834 100644
--- a/searx/engines/openstreetmap.py
+++ b/searx/engines/openstreetmap.py
@@ -151,10 +151,12 @@ def response(resp):
     user_language = resp.search_params['language']
 
     if resp.search_params['route']:
-        results.append({
-            'answer': gettext('Get directions'),
-            'url': route_url.format(*resp.search_params['route'].groups()),
-            })
+        results.append(
+            {
+                'answer': gettext('Get directions'),
+                'url': route_url.format(*resp.search_params['route'].groups()),
+            }
+        )
 
     fetch_wikidata(nominatim_json, user_language)
 
@@ -170,26 +172,26 @@ def response(resp):
         links, link_keys = get_links(result, user_language)
         data = get_data(result, user_language, link_keys)
 
-        results.append({
-            'template': 'map.html',
-            'title': title,
-            'address': address,
-            'address_label': get_key_label('addr', user_language),
-            'url': url,
-            'osm': osm,
-            'geojson': geojson,
-            'img_src': img_src,
-            'links': links,
-            'data': data,
-            'type': get_tag_label(
-                result.get('category'), result.get('type', ''), user_language
-            ),
-            'type_icon': result.get('icon'),
-            'content': '',
-            'longitude': result['lon'],
-            'latitude': result['lat'],
-            'boundingbox': result['boundingbox'],
-        })
+        results.append(
+            {
+                'template': 'map.html',
+                'title': title,
+                'address': address,
+                'address_label': get_key_label('addr', user_language),
+                'url': url,
+                'osm': osm,
+                'geojson': geojson,
+                'img_src': img_src,
+                'links': links,
+                'data': data,
+                'type': get_tag_label(result.get('category'), result.get('type', ''), user_language),
+                'type_icon': result.get('icon'),
+                'content': '',
+                'longitude': result['lon'],
+                'latitude': result['lat'],
+                'boundingbox': result['boundingbox'],
+            }
+        )
 
     return results
 
@@ -270,9 +272,9 @@ def get_title_address(result):
             # https://github.com/osm-search/Nominatim/issues/1662
             address_name = address_raw.get('address29')
         else:
-            address_name =  address_raw.get(result['category'])
+            address_name = address_raw.get(result['category'])
     elif result['type'] in address_raw:
-        address_name =  address_raw.get(result['type'])
+        address_name = address_raw.get(result['type'])
 
     # add rest of adressdata, if something is already found
     if address_name:
@@ -297,8 +299,7 @@ def get_title_address(result):
 
 
 def get_url_osm_geojson(result):
-    """Get url, osm and geojson
-    """
+    """Get url, osm and geojson"""
     osm_type = result.get('osm_type', result.get('type'))
     if 'osm_id' not in result:
         # see https://github.com/osm-search/Nominatim/issues/1521
@@ -349,11 +350,13 @@ def get_links(result, user_language):
             url, url_label = mapping_function(raw_value)
             if url.startswith('https://wikidata.org'):
                 url_label = result.get('wikidata', {}).get('itemLabel') or url_label
-            links.append({
-                'label': get_key_label(k, user_language),
-                'url': url,
-                'url_label': url_label,
-            })
+            links.append(
+                {
+                    'label': get_key_label(k, user_language),
+                    'url': url,
+                    'url_label': url_label,
+                }
+            )
             link_keys.add(k)
     return links, link_keys
 
@@ -373,11 +376,13 @@ def get_data(result, user_language, ignore_keys):
             continue
         k_label = get_key_label(k, user_language)
         if k_label:
-            data.append({
-                'label': k_label,
-                'key': k,
-                'value': v,
-            })
+            data.append(
+                {
+                    'label': k_label,
+                    'key': k,
+                    'value': v,
+                }
+            )
     data.sort(key=lambda entry: (get_key_rank(entry['key']), entry['label']))
     return data
 
diff --git a/searx/engines/pdbe.py b/searx/engines/pdbe.py
index b9bbfaf1b..34c8d3227 100644
--- a/searx/engines/pdbe.py
+++ b/searx/engines/pdbe.py
@@ -34,10 +34,7 @@ def request(query, params):
 
     params['url'] = pdbe_solr_url
     params['method'] = 'POST'
-    params['data'] = {
-        'q': query,
-        'wt': "json"  # request response in parsable format
-    }
+    params['data'] = {'q': query, 'wt': "json"}  # request response in parsable format
     return params
 
 
@@ -53,12 +50,21 @@ def construct_body(result):
         if result['journal']:
             content = content.format(
                 title=result['citation_title'],
-                authors=result['entry_author_list'][0], journal=result['journal'], volume=result['journal_volume'],
-                page=result['journal_page'], year=result['citation_year'])
+                authors=result['entry_author_list'][0],
+                journal=result['journal'],
+                volume=result['journal_volume'],
+                page=result['journal_page'],
+                year=result['citation_year'],
+            )
         else:
             content = content.format(
                 title=result['citation_title'],
-                authors=result['entry_author_list'][0], journal='', volume='', page='', year=result['release_year'])
+                authors=result['entry_author_list'][0],
+                journal='',
+                volume='',
+                page='',
+                year=result['release_year'],
+            )
         img_src = pdbe_preview_url.format(pdb_id=result['pdb_id'])
     except (KeyError):
         content = None
@@ -96,20 +102,21 @@ def response(resp):
             # since we can't construct a proper body from the response, we'll make up our own
             msg_superseded = gettext("This entry has been superseded by")
             content = '{msg_superseded}: {url} ({pdb_id})'.format(
-                msg_superseded=msg_superseded,
-                url=superseded_url,
-                pdb_id=result['superseded_by'])
+                msg_superseded=msg_superseded, url=superseded_url, pdb_id=result['superseded_by']
+            )
 
             # obsoleted entries don't have preview images
             img_src = None
         else:
             title, content, img_src = construct_body(result)
 
-        results.append({
-            'url': pdbe_entry_url.format(pdb_id=result['pdb_id']),
-            'title': title,
-            'content': content,
-            'img_src': img_src
-        })
+        results.append(
+            {
+                'url': pdbe_entry_url.format(pdb_id=result['pdb_id']),
+                'title': title,
+                'content': content,
+                'img_src': img_src,
+            }
+        )
 
     return results
diff --git a/searx/engines/peertube.py b/searx/engines/peertube.py
index f9cd50be1..1ace14027 100644
--- a/searx/engines/peertube.py
+++ b/searx/engines/peertube.py
@@ -36,9 +36,7 @@ def request(query, params):
     language = params["language"].split("-")[0]
     if "all" != language and language in supported_languages:
         query_dict["languageOneOf"] = language
-    params["url"] = search_url.format(
-        query=urlencode(query_dict), pageno=pageno
-    )
+    params["url"] = search_url.format(query=urlencode(query_dict), pageno=pageno)
     return params
 
 
diff --git a/searx/engines/photon.py b/searx/engines/photon.py
index f85dcad86..16ea88194 100644
--- a/searx/engines/photon.py
+++ b/searx/engines/photon.py
@@ -33,9 +33,7 @@ supported_languages = ['de', 'en', 'fr', 'it']
 
 # do search-request
 def request(query, params):
-    params['url'] = base_url +\
-        search_string.format(query=urlencode({'q': query}),
-                             limit=number_of_results)
+    params['url'] = base_url + search_string.format(query=urlencode({'q': query}), limit=number_of_results)
 
     if params['language'] != 'all':
         language = params['language'].split('_')[0]
@@ -75,59 +73,71 @@ def response(resp):
             # continue if invalide osm-type
             continue
 
-        url = result_base_url.format(osm_type=osm_type,
-                                     osm_id=properties.get('osm_id'))
+        url = result_base_url.format(osm_type=osm_type, osm_id=properties.get('osm_id'))
 
-        osm = {'type': osm_type,
-               'id': properties.get('osm_id')}
+        osm = {'type': osm_type, 'id': properties.get('osm_id')}
 
         geojson = r.get('geometry')
 
         if properties.get('extent'):
-            boundingbox = [properties.get('extent')[3],
-                           properties.get('extent')[1],
-                           properties.get('extent')[0],
-                           properties.get('extent')[2]]
+            boundingbox = [
+                properties.get('extent')[3],
+                properties.get('extent')[1],
+                properties.get('extent')[0],
+                properties.get('extent')[2],
+            ]
         else:
             # TODO: better boundingbox calculation
-            boundingbox = [geojson['coordinates'][1],
-                           geojson['coordinates'][1],
-                           geojson['coordinates'][0],
-                           geojson['coordinates'][0]]
+            boundingbox = [
+                geojson['coordinates'][1],
+                geojson['coordinates'][1],
+                geojson['coordinates'][0],
+                geojson['coordinates'][0],
+            ]
 
         # address calculation
         address = {}
 
         # get name
-        if properties.get('osm_key') == 'amenity' or\
-           properties.get('osm_key') == 'shop' or\
-           properties.get('osm_key') == 'tourism' or\
-           properties.get('osm_key') == 'leisure':
+        if (
+            properties.get('osm_key') == 'amenity'
+            or properties.get('osm_key') == 'shop'
+            or properties.get('osm_key') == 'tourism'
+            or properties.get('osm_key') == 'leisure'
+        ):
             address = {'name': properties.get('name')}
 
         # add rest of adressdata, if something is already found
         if address.get('name'):
-            address.update({'house_number': properties.get('housenumber'),
-                           'road': properties.get('street'),
-                           'locality': properties.get('city',
-                                       properties.get('town',           # noqa
-                                       properties.get('village'))),     # noqa
-                           'postcode': properties.get('postcode'),
-                           'country': properties.get('country')})
+            address.update(
+                {
+                    'house_number': properties.get('housenumber'),
+                    'road': properties.get('street'),
+                    'locality': properties.get(
+                        'city', properties.get('town', properties.get('village'))  # noqa
+                    ),  # noqa
+                    'postcode': properties.get('postcode'),
+                    'country': properties.get('country'),
+                }
+            )
         else:
             address = None
 
         # append result
-        results.append({'template': 'map.html',
-                        'title': title,
-                        'content': '',
-                        'longitude': geojson['coordinates'][0],
-                        'latitude': geojson['coordinates'][1],
-                        'boundingbox': boundingbox,
-                        'geojson': geojson,
-                        'address': address,
-                        'osm': osm,
-                        'url': url})
+        results.append(
+            {
+                'template': 'map.html',
+                'title': title,
+                'content': '',
+                'longitude': geojson['coordinates'][0],
+                'latitude': geojson['coordinates'][1],
+                'boundingbox': boundingbox,
+                'geojson': geojson,
+                'address': address,
+                'osm': osm,
+                'url': url,
+            }
+        )
 
     # return results
     return results
diff --git a/searx/engines/piratebay.py b/searx/engines/piratebay.py
index d4b94ecfa..4b0984be5 100644
--- a/searx/engines/piratebay.py
+++ b/searx/engines/piratebay.py
@@ -40,17 +40,14 @@ trackers = [
 ]
 
 # piratebay specific type-definitions
-search_types = {"files": "0",
-                "music": "100",
-                "videos": "200"}
+search_types = {"files": "0", "music": "100", "videos": "200"}
 
 
 # do search-request
 def request(query, params):
     search_type = search_types.get(params["category"], "0")
 
-    params["url"] = search_url.format(search_term=quote(query),
-                                      search_type=search_type)
+    params["url"] = search_url.format(search_term=quote(query), search_type=search_type)
 
     return params
 
@@ -68,8 +65,9 @@ def response(resp):
     # parse results
     for result in search_res:
         link = url + "description.php?id=" + result["id"]
-        magnetlink = "magnet:?xt=urn:btih:" + result["info_hash"] + "&dn=" + result["name"]\
-                     + "&tr=" + "&tr=".join(trackers)
+        magnetlink = (
+            "magnet:?xt=urn:btih:" + result["info_hash"] + "&dn=" + result["name"] + "&tr=" + "&tr=".join(trackers)
+        )
 
         params = {
             "url": link,
@@ -77,7 +75,7 @@ def response(resp):
             "seed": result["seeders"],
             "leech": result["leechers"],
             "magnetlink": magnetlink,
-            "template": "torrent.html"
+            "template": "torrent.html",
         }
 
         # extract and convert creation date
diff --git a/searx/engines/postgresql.py b/searx/engines/postgresql.py
index 1eddcd519..d8bbabe27 100644
--- a/searx/engines/postgresql.py
+++ b/searx/engines/postgresql.py
@@ -20,6 +20,7 @@ paging = True
 result_template = 'key-value.html'
 _connection = None
 
+
 def init(engine_settings):
     global _connection  # pylint: disable=global-statement
 
@@ -30,25 +31,24 @@ def init(engine_settings):
         raise ValueError('only SELECT query is supported')
 
     _connection = psycopg2.connect(
-        database = database,
-        user = username,
-        password = password,
-        host = host,
-        port = port,
+        database=database,
+        user=username,
+        password=password,
+        host=host,
+        port=port,
     )
 
+
 def search(query, params):
     query_params = {'query': query}
-    query_to_run = (
-        query_str
-        + ' LIMIT {0} OFFSET {1}'.format(limit, (params['pageno'] - 1) * limit)
-    )
+    query_to_run = query_str + ' LIMIT {0} OFFSET {1}'.format(limit, (params['pageno'] - 1) * limit)
 
     with _connection:
         with _connection.cursor() as cur:
             cur.execute(query_to_run, query_params)
             return _fetch_results(cur)
 
+
 def _fetch_results(cur):
     results = []
     titles = []
diff --git a/searx/engines/pubmed.py b/searx/engines/pubmed.py
index 5d88d398e..27444ae24 100644
--- a/searx/engines/pubmed.py
+++ b/searx/engines/pubmed.py
@@ -15,7 +15,7 @@ about = {
     "wikidata_id": 'Q1540899',
     "official_api_documentation": {
         'url': 'https://www.ncbi.nlm.nih.gov/home/develop/api/',
-        'comment': 'More info on api: https://www.ncbi.nlm.nih.gov/books/NBK25501/'
+        'comment': 'More info on api: https://www.ncbi.nlm.nih.gov/books/NBK25501/',
     },
     "use_official_api": True,
     "require_api_key": False,
@@ -24,8 +24,9 @@ about = {
 
 categories = ['science']
 
-base_url = 'https://eutils.ncbi.nlm.nih.gov/entrez/eutils/esearch.fcgi'\
-           + '?db=pubmed&{query}&retstart={offset}&retmax={hits}'
+base_url = (
+    'https://eutils.ncbi.nlm.nih.gov/entrez/eutils/esearch.fcgi' + '?db=pubmed&{query}&retstart={offset}&retmax={hits}'
+)
 
 # engine dependent config
 number_of_results = 10
@@ -36,9 +37,7 @@ def request(query, params):
     # basic search
     offset = (params['pageno'] - 1) * number_of_results
 
-    string_args = dict(query=urlencode({'term': query}),
-                       offset=offset,
-                       hits=number_of_results)
+    string_args = dict(query=urlencode({'term': query}), offset=offset, hits=number_of_results)
 
     params['url'] = base_url.format(**string_args)
 
@@ -49,8 +48,9 @@ def response(resp):
     results = []
 
     # First retrieve notice of each result
-    pubmed_retrieve_api_url = 'https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?'\
-                              + 'db=pubmed&retmode=xml&id={pmids_string}'
+    pubmed_retrieve_api_url = (
+        'https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?' + 'db=pubmed&retmode=xml&id={pmids_string}'
+    )
 
     pmids_results = etree.XML(resp.content)
     pmids = pmids_results.xpath('//eSearchResult/IdList/Id')
@@ -88,14 +88,17 @@ def response(resp):
             content = content[0:300] + "..."
         # TODO: center snippet on query term
 
-        res_dict = {'url': url,
-                    'title': title,
-                    'content': content}
+        res_dict = {'url': url, 'title': title, 'content': content}
 
         try:
-            publishedDate = datetime.strptime(entry.xpath('.//DateCreated/Year')[0].text
-                                              + '-' + entry.xpath('.//DateCreated/Month')[0].text
-                                              + '-' + entry.xpath('.//DateCreated/Day')[0].text, '%Y-%m-%d')
+            publishedDate = datetime.strptime(
+                entry.xpath('.//DateCreated/Year')[0].text
+                + '-'
+                + entry.xpath('.//DateCreated/Month')[0].text
+                + '-'
+                + entry.xpath('.//DateCreated/Day')[0].text,
+                '%Y-%m-%d',
+            )
             res_dict['publishedDate'] = publishedDate
         except:
             pass
diff --git a/searx/engines/qwant.py b/searx/engines/qwant.py
index 0312e518c..a1799491a 100644
--- a/searx/engines/qwant.py
+++ b/searx/engines/qwant.py
@@ -61,6 +61,7 @@ category_to_keyword = {
 # search-url
 url = 'https://api.qwant.com/v3/search/{keyword}?{query}&count={count}&offset={offset}'
 
+
 def request(query, params):
     """Qwant search request"""
     keyword = category_to_keyword[categories[0]]
@@ -77,10 +78,10 @@ def request(query, params):
         offset = min(offset, 40)
 
     params['url'] = url.format(
-        keyword = keyword,
-        query = urlencode({'q': query}),
-        offset = offset,
-        count = count,
+        keyword=keyword,
+        query=urlencode({'q': query}),
+        offset=offset,
+        count=count,
     )
 
     # add language tag
@@ -111,7 +112,14 @@ def response(resp):
 
     # check for an API error
     if search_results.get('status') != 'success':
-        msg = ",".join(data.get('message', ['unknown', ]))
+        msg = ",".join(
+            data.get(
+                'message',
+                [
+                    'unknown',
+                ],
+            )
+        )
         raise SearxEngineAPIException('API error::' + msg)
 
     # raise for other errors
@@ -128,7 +136,7 @@ def response(resp):
         # result['items'].
         mainline = data.get('result', {}).get('items', [])
         mainline = [
-            {'type' : keyword, 'items' : mainline },
+            {'type': keyword, 'items': mainline},
         ]
 
     # return empty array if there are no results
@@ -153,11 +161,13 @@ def response(resp):
 
             if mainline_type == 'web':
                 content = item['desc']
-                results.append({
-                    'title': title,
-                    'url': res_url,
-                    'content': content,
-                })
+                results.append(
+                    {
+                        'title': title,
+                        'url': res_url,
+                        'content': content,
+                    }
+                )
 
             elif mainline_type == 'news':
 
@@ -168,23 +178,27 @@ def response(resp):
                 img_src = None
                 if news_media:
                     img_src = news_media[0].get('pict', {}).get('url', None)
-                results.append({
-                    'title': title,
-                    'url': res_url,
-                    'publishedDate': pub_date,
-                    'img_src': img_src,
-                })
+                results.append(
+                    {
+                        'title': title,
+                        'url': res_url,
+                        'publishedDate': pub_date,
+                        'img_src': img_src,
+                    }
+                )
 
             elif mainline_type == 'images':
                 thumbnail = item['thumbnail']
                 img_src = item['media']
-                results.append({
-                    'title': title,
-                    'url': res_url,
-                    'template': 'images.html',
-                    'thumbnail_src': thumbnail,
-                    'img_src': img_src,
-                })
+                results.append(
+                    {
+                        'title': title,
+                        'url': res_url,
+                        'template': 'images.html',
+                        'thumbnail_src': thumbnail,
+                        'img_src': img_src,
+                    }
+                )
 
             elif mainline_type == 'videos':
                 # some videos do not have a description: while qwant-video
@@ -208,19 +222,18 @@ def response(resp):
                 thumbnail = item['thumbnail']
                 # from some locations (DE and others?) the s2 link do
                 # response a 'Please wait ..' but does not deliver the thumbnail
-                thumbnail = thumbnail.replace(
-                    'https://s2.qwant.com',
-                    'https://s1.qwant.com', 1
+                thumbnail = thumbnail.replace('https://s2.qwant.com', 'https://s1.qwant.com', 1)
+                results.append(
+                    {
+                        'title': title,
+                        'url': res_url,
+                        'content': content,
+                        'publishedDate': pub_date,
+                        'thumbnail': thumbnail,
+                        'template': 'videos.html',
+                        'length': length,
+                    }
                 )
-                results.append({
-                    'title': title,
-                    'url': res_url,
-                    'content': content,
-                    'publishedDate': pub_date,
-                    'thumbnail': thumbnail,
-                    'template': 'videos.html',
-                    'length':  length,
-            })
 
     return results
 
@@ -229,8 +242,8 @@ def response(resp):
 def _fetch_supported_languages(resp):
     # list of regions is embedded in page as a js object
     response_text = resp.text
-    response_text = response_text[response_text.find('INITIAL_PROPS'):]
-    response_text = response_text[response_text.find('{'):response_text.find('</script>')]
+    response_text = response_text[response_text.find('INITIAL_PROPS') :]
+    response_text = response_text[response_text.find('{') : response_text.find('</script>')]
 
     regions_json = loads(response_text)
 
diff --git a/searx/engines/recoll.py b/searx/engines/recoll.py
index 42f2858d7..ebcd83b8d 100644
--- a/searx/engines/recoll.py
+++ b/searx/engines/recoll.py
@@ -28,18 +28,12 @@ mount_prefix = None
 dl_prefix = None
 
 # embedded
-embedded_url = '<{ttype} controls height="166px" ' +\
-    'src="{url}" type="{mtype}"></{ttype}>'
+embedded_url = '<{ttype} controls height="166px" ' + 'src="{url}" type="{mtype}"></{ttype}>'
 
 
 # helper functions
 def get_time_range(time_range):
-    sw = {
-        'day': 1,
-        'week': 7,
-        'month': 30,
-        'year': 365
-    }
+    sw = {'day': 1, 'week': 7, 'month': 30, 'year': 365}
 
     offset = sw.get(time_range, 0)
     if not offset:
@@ -52,11 +46,9 @@ def get_time_range(time_range):
 def request(query, params):
     search_after = get_time_range(params['time_range'])
     search_url = base_url + 'json?{query}&highlight=0'
-    params['url'] = search_url.format(query=urlencode({
-        'query': query,
-        'page': params['pageno'],
-        'after': search_after,
-        'dir': search_dir}))
+    params['url'] = search_url.format(
+        query=urlencode({'query': query, 'page': params['pageno'], 'after': search_after, 'dir': search_dir})
+    )
 
     return params
 
@@ -76,10 +68,7 @@ def response(resp):
         content = '{}'.format(result['snippet'])
 
         # append result
-        item = {'url': url,
-                'title': title,
-                'content': content,
-                'template': 'files.html'}
+        item = {'url': url, 'title': title, 'content': content, 'template': 'files.html'}
 
         if result['size']:
             item['size'] = int(result['size'])
@@ -96,9 +85,8 @@ def response(resp):
 
             if mtype in ['audio', 'video']:
                 item['embedded'] = embedded_url.format(
-                    ttype=mtype,
-                    url=quote(url.encode('utf8'), '/:'),
-                    mtype=result['mtype'])
+                    ttype=mtype, url=quote(url.encode('utf8'), '/:'), mtype=result['mtype']
+                )
 
             if mtype in ['image'] and subtype in ['bmp', 'gif', 'jpeg', 'png']:
                 item['img_src'] = url
diff --git a/searx/engines/reddit.py b/searx/engines/reddit.py
index ca6cb28a8..36d92339d 100644
--- a/searx/engines/reddit.py
+++ b/searx/engines/reddit.py
@@ -52,10 +52,7 @@ def response(resp):
         data = post['data']
 
         # extract post information
-        params = {
-            'url': urljoin(base_url, data['permalink']),
-            'title': data['title']
-        }
+        params = {'url': urljoin(base_url, data['permalink']), 'title': data['title']}
 
         # if thumbnail field contains a valid URL, we need to change template
         thumbnail = data['thumbnail']
diff --git a/searx/engines/redis_server.py b/searx/engines/redis_server.py
index f9726033d..03786f81d 100644
--- a/searx/engines/redis_server.py
+++ b/searx/engines/redis_server.py
@@ -20,16 +20,19 @@ result_template = 'key-value.html'
 exact_match_only = True
 
 _redis_client = None
+
+
 def init(_engine_settings):
     global _redis_client  # pylint: disable=global-statement
     _redis_client = redis.StrictRedis(
-        host = host,
-        port = port,
-        db = db,
-        password = password or None,
-        decode_responses = True,
+        host=host,
+        port=port,
+        db=db,
+        password=password or None,
+        decode_responses=True,
     )
 
+
 def search(query, _params):
     if not exact_match_only:
         return search_keys(query)
@@ -42,21 +45,20 @@ def search(query, _params):
     if ' ' in query:
         qset, rest = query.split(' ', 1)
         ret = []
-        for res in _redis_client.hscan_iter(
-                qset, match='*{}*'.format(rest)
-        ):
-            ret.append({
-                res[0]: res[1],
-                'template': result_template,
-            })
+        for res in _redis_client.hscan_iter(qset, match='*{}*'.format(rest)):
+            ret.append(
+                {
+                    res[0]: res[1],
+                    'template': result_template,
+                }
+            )
         return ret
     return []
 
+
 def search_keys(query):
     ret = []
-    for key in _redis_client.scan_iter(
-            match='*{}*'.format(query)
-    ):
+    for key in _redis_client.scan_iter(match='*{}*'.format(query)):
         key_type = _redis_client.type(key)
         res = None
 
diff --git a/searx/engines/rumble.py b/searx/engines/rumble.py
index 407142467..beca2570c 100644
--- a/searx/engines/rumble.py
+++ b/searx/engines/rumble.py
@@ -68,14 +68,16 @@ def response(resp):
         else:
             content = f"{views} views - {rumbles} rumbles"
 
-        results.append({
-            'url': url,
-            'title': title,
-            'content': content,
-            'author': author,
-            'length': length,
-            'template': 'videos.html',
-            'publishedDate': fixed_date,
-            'thumbnail': thumbnail,
-        })
+        results.append(
+            {
+                'url': url,
+                'title': title,
+                'content': content,
+                'author': author,
+                'length': length,
+                'template': 'videos.html',
+                'publishedDate': fixed_date,
+                'thumbnail': thumbnail,
+            }
+        )
     return results
diff --git a/searx/engines/scanr_structures.py b/searx/engines/scanr_structures.py
index 51c925247..ad27079dd 100644
--- a/searx/engines/scanr_structures.py
+++ b/searx/engines/scanr_structures.py
@@ -32,12 +32,16 @@ def request(query, params):
     params['url'] = search_url
     params['method'] = 'POST'
     params['headers']['Content-type'] = "application/json"
-    params['data'] = dumps({"query": query,
-                            "searchField": "ALL",
-                            "sortDirection": "ASC",
-                            "sortOrder": "RELEVANCY",
-                            "page": params['pageno'],
-                            "pageSize": page_size})
+    params['data'] = dumps(
+        {
+            "query": query,
+            "searchField": "ALL",
+            "sortDirection": "ASC",
+            "sortOrder": "RELEVANCY",
+            "page": params['pageno'],
+            "pageSize": page_size,
+        }
+    )
 
     return params
 
@@ -69,11 +73,15 @@ def response(resp):
             content = result['highlights'][0]['value']
 
         # append result
-        results.append({'url': url + 'structure/' + result['id'],
-                        'title': result['label'],
-                        # 'thumbnail': thumbnail,
-                        'img_src': thumbnail,
-                        'content': html_to_text(content)})
+        results.append(
+            {
+                'url': url + 'structure/' + result['id'],
+                'title': result['label'],
+                # 'thumbnail': thumbnail,
+                'img_src': thumbnail,
+                'content': html_to_text(content),
+            }
+        )
 
     # return results
     return results
diff --git a/searx/engines/searchcode_code.py b/searx/engines/searchcode_code.py
index 8c1330d98..a4b0308f9 100644
--- a/searx/engines/searchcode_code.py
+++ b/searx/engines/searchcode_code.py
@@ -25,10 +25,7 @@ url = 'https://searchcode.com/'
 search_url = url + 'api/codesearch_I/?{query}&p={pageno}'
 
 # special code-endings which are not recognised by the file ending
-code_endings = {'cs': 'c#',
-                'h': 'c',
-                'hpp': 'cpp',
-                'cxx': 'cpp'}
+code_endings = {'cs': 'c#', 'h': 'c', 'hpp': 'cpp', 'cxx': 'cpp'}
 
 
 # do search-request
@@ -55,17 +52,21 @@ def response(resp):
             lines[int(line)] = code
 
         code_language = code_endings.get(
-            result['filename'].split('.')[-1].lower(),
-            result['filename'].split('.')[-1].lower())
+            result['filename'].split('.')[-1].lower(), result['filename'].split('.')[-1].lower()
+        )
 
         # append result
-        results.append({'url': href,
-                        'title': title,
-                        'content': '',
-                        'repository': repo,
-                        'codelines': sorted(lines.items()),
-                        'code_language': code_language,
-                        'template': 'code.html'})
+        results.append(
+            {
+                'url': href,
+                'title': title,
+                'content': '',
+                'repository': repo,
+                'codelines': sorted(lines.items()),
+                'code_language': code_language,
+                'template': 'code.html',
+            }
+        )
 
     # return results
     return results
diff --git a/searx/engines/searx_engine.py b/searx/engines/searx_engine.py
index 98ef0fb79..3e9035d6f 100644
--- a/searx/engines/searx_engine.py
+++ b/searx/engines/searx_engine.py
@@ -37,7 +37,7 @@ def request(query, params):
         'language': params['language'],
         'time_range': params['time_range'],
         'category': params['category'],
-        'format': 'json'
+        'format': 'json',
     }
 
     return params
diff --git a/searx/engines/semantic_scholar.py b/searx/engines/semantic_scholar.py
index 297d0cf71..5d9d1a8e9 100644
--- a/searx/engines/semantic_scholar.py
+++ b/searx/engines/semantic_scholar.py
@@ -13,19 +13,21 @@ def request(query, params):
     params['url'] = search_url
     params['method'] = 'POST'
     params['headers']['content-type'] = 'application/json'
-    params['data'] = dumps({
-        "queryString": query,
-        "page": params['pageno'],
-        "pageSize": 10,
-        "sort": "relevance",
-        "useFallbackRankerService": False,
-        "useFallbackSearchCluster": False,
-        "getQuerySuggestions": False,
-        "authors": [],
-        "coAuthors": [],
-        "venues": [],
-        "performTitleMatch": True,
-    })
+    params['data'] = dumps(
+        {
+            "queryString": query,
+            "page": params['pageno'],
+            "pageSize": 10,
+            "sort": "relevance",
+            "useFallbackRankerService": False,
+            "useFallbackSearchCluster": False,
+            "getQuerySuggestions": False,
+            "authors": [],
+            "coAuthors": [],
+            "venues": [],
+            "performTitleMatch": True,
+        }
+    )
     return params
 
 
@@ -33,10 +35,12 @@ def response(resp):
     res = loads(resp.text)
     results = []
     for result in res['results']:
-        results.append({
-            'url': result['primaryPaperLink']['url'],
-            'title': result['title']['text'],
-            'content': result['paperAbstractTruncated']
-        })
+        results.append(
+            {
+                'url': result['primaryPaperLink']['url'],
+                'title': result['title']['text'],
+                'content': result['paperAbstractTruncated'],
+            }
+        )
 
     return results
diff --git a/searx/engines/sepiasearch.py b/searx/engines/sepiasearch.py
index ebad20d01..00b1b3672 100644
--- a/searx/engines/sepiasearch.py
+++ b/searx/engines/sepiasearch.py
@@ -31,17 +31,13 @@ supported_languages = [
 ]
 base_url = 'https://sepiasearch.org/api/v1/search/videos'
 
-safesearch_table = {
-    0: 'both',
-    1: 'false',
-    2: 'false'
-}
+safesearch_table = {0: 'both', 1: 'false', 2: 'false'}
 
 time_range_table = {
     'day': relativedelta.relativedelta(),
     'week': relativedelta.relativedelta(weeks=-1),
     'month': relativedelta.relativedelta(months=-1),
-    'year': relativedelta.relativedelta(years=-1)
+    'year': relativedelta.relativedelta(years=-1),
 }
 
 
@@ -55,13 +51,19 @@ def minute_to_hm(minute):
 
 
 def request(query, params):
-    params['url'] = base_url + '?' + urlencode({
-        'search': query,
-        'start': (params['pageno'] - 1) * 10,
-        'count': 10,
-        'sort': '-match',
-        'nsfw': safesearch_table[params['safesearch']]
-    })
+    params['url'] = (
+        base_url
+        + '?'
+        + urlencode(
+            {
+                'search': query,
+                'start': (params['pageno'] - 1) * 10,
+                'count': 10,
+                'sort': '-match',
+                'nsfw': safesearch_table[params['safesearch']],
+            }
+        )
+    )
 
     language = params['language'].split('-')[0]
     if language in supported_languages:
@@ -91,14 +93,18 @@ def response(resp):
         length = minute_to_hm(result.get('duration'))
         url = result['url']
 
-        results.append({'url': url,
-                        'title': title,
-                        'content': content,
-                        'author': author,
-                        'length': length,
-                        'template': 'videos.html',
-                        'publishedDate': publishedDate,
-                        'embedded': embedded,
-                        'thumbnail': thumbnail})
+        results.append(
+            {
+                'url': url,
+                'title': title,
+                'content': content,
+                'author': author,
+                'length': length,
+                'template': 'videos.html',
+                'publishedDate': publishedDate,
+                'embedded': embedded,
+                'thumbnail': thumbnail,
+            }
+        )
 
     return results
diff --git a/searx/engines/seznam.py b/searx/engines/seznam.py
index 85cb25b7f..2e95b4769 100644
--- a/searx/engines/seznam.py
+++ b/searx/engines/seznam.py
@@ -58,10 +58,12 @@ def response(resp):
         if result_data is None:
             continue
         title_element = eval_xpath_getindex(result_element, './/h3/a', 0)
-        results.append({
-            'url': title_element.get('href'),
-            'title': extract_text(title_element),
-            'content': extract_text(eval_xpath(result_data, './/div[@class="_3eded7"]')),
-        })
+        results.append(
+            {
+                'url': title_element.get('href'),
+                'title': extract_text(title_element),
+                'content': extract_text(eval_xpath(result_data, './/div[@class="_3eded7"]')),
+            }
+        )
 
     return results
diff --git a/searx/engines/sjp.py b/searx/engines/sjp.py
index 884fddd2d..ad498b847 100644
--- a/searx/engines/sjp.py
+++ b/searx/engines/sjp.py
@@ -28,9 +28,11 @@ URL = 'https://sjp.pwn.pl'
 SEARCH_URL = URL + '/szukaj/{query}.html'
 
 word_xpath = '//div[@class="query"]'
-dict_xpath = ['//div[@class="wyniki sjp-so-wyniki sjp-so-anchor"]',
-              '//div[@class="wyniki sjp-wyniki sjp-anchor"]',
-              '//div[@class="wyniki sjp-doroszewski-wyniki sjp-doroszewski-anchor"]']
+dict_xpath = [
+    '//div[@class="wyniki sjp-so-wyniki sjp-so-anchor"]',
+    '//div[@class="wyniki sjp-wyniki sjp-anchor"]',
+    '//div[@class="wyniki sjp-doroszewski-wyniki sjp-doroszewski-anchor"]',
+]
 
 
 def request(query, params):
@@ -85,9 +87,11 @@ def response(resp):
                 infobox += "</ol>"
         infobox += "</ul></div>"
 
-    results.append({
-        'infobox': word,
-        'content': infobox,
-    })
+    results.append(
+        {
+            'infobox': word,
+            'content': infobox,
+        }
+    )
 
     return results
diff --git a/searx/engines/solidtorrents.py b/searx/engines/solidtorrents.py
index 7fbef9190..614b38277 100644
--- a/searx/engines/solidtorrents.py
+++ b/searx/engines/solidtorrents.py
@@ -36,14 +36,16 @@ def response(resp):
     search_results = loads(resp.text)
 
     for result in search_results["results"]:
-        results.append({
-            'infohash': result["infohash"],
-            'seed': result["swarm"]["seeders"],
-            'leech': result["swarm"]["leechers"],
-            'title': result["title"],
-            'url': "https://solidtorrents.net/view/" + result["_id"],
-            'filesize': result["size"],
-            'magnetlink': result["magnet"],
-            'template': "torrent.html",
-        })
+        results.append(
+            {
+                'infohash': result["infohash"],
+                'seed': result["swarm"]["seeders"],
+                'leech': result["swarm"]["leechers"],
+                'title': result["title"],
+                'url': "https://solidtorrents.net/view/" + result["_id"],
+                'filesize': result["size"],
+                'magnetlink': result["magnet"],
+                'template': "torrent.html",
+            }
+        )
     return results
diff --git a/searx/engines/solr.py b/searx/engines/solr.py
index e26f19442..3e7846f8e 100644
--- a/searx/engines/solr.py
+++ b/searx/engines/solr.py
@@ -14,10 +14,10 @@ from searx.exceptions import SearxEngineAPIException
 base_url = 'http://localhost:8983'
 collection = ''
 rows = 10
-sort = '' # sorting: asc or desc
-field_list = 'name' # list of field names to display on the UI
-default_fields = '' # default field to query
-query_fields = '' # query fields
+sort = ''  # sorting: asc or desc
+field_list = 'name'  # list of field names to display on the UI
+default_fields = ''  # default field to query
+query_fields = ''  # query fields
 _search_url = ''
 paging = True
 
diff --git a/searx/engines/soundcloud.py b/searx/engines/soundcloud.py
index d5bfc0f6f..004164e37 100644
--- a/searx/engines/soundcloud.py
+++ b/searx/engines/soundcloud.py
@@ -27,17 +27,21 @@ paging = True
 # search-url
 # missing attribute: user_id, app_version, app_locale
 url = 'https://api-v2.soundcloud.com/'
-search_url = url + 'search?{query}'\
-                         '&variant_ids='\
-                         '&facet=model'\
-                         '&limit=20'\
-                         '&offset={offset}'\
-                         '&linked_partitioning=1'\
-                         '&client_id={client_id}'   # noqa
-
-embedded_url = '<iframe width="100%" height="166" ' +\
-    'scrolling="no" frameborder="no" ' +\
-    'data-src="https://w.soundcloud.com/player/?url={uri}"></iframe>'
+search_url = (
+    url + 'search?{query}'
+    '&variant_ids='
+    '&facet=model'
+    '&limit=20'
+    '&offset={offset}'
+    '&linked_partitioning=1'
+    '&client_id={client_id}'
+)  # noqa
+
+embedded_url = (
+    '<iframe width="100%" height="166" '
+    + 'scrolling="no" frameborder="no" '
+    + 'data-src="https://w.soundcloud.com/player/?url={uri}"></iframe>'
+)
 
 cid_re = re.compile(r'client_id:"([^"]*)"', re.I | re.U)
 guest_client_id = ''
@@ -75,9 +79,7 @@ def init(engine_settings=None):
 def request(query, params):
     offset = (params['pageno'] - 1) * 20
 
-    params['url'] = search_url.format(query=urlencode({'q': query}),
-                                      offset=offset,
-                                      client_id=guest_client_id)
+    params['url'] = search_url.format(query=urlencode({'q': query}), offset=offset, client_id=guest_client_id)
 
     return params
 
@@ -98,11 +100,15 @@ def response(resp):
             embedded = embedded_url.format(uri=uri)
 
             # append result
-            results.append({'url': result['permalink_url'],
-                            'title': title,
-                            'publishedDate': publishedDate,
-                            'embedded': embedded,
-                            'content': content})
+            results.append(
+                {
+                    'url': result['permalink_url'],
+                    'title': title,
+                    'publishedDate': publishedDate,
+                    'embedded': embedded,
+                    'content': content,
+                }
+            )
 
     # return results
     return results
diff --git a/searx/engines/spotify.py b/searx/engines/spotify.py
index 6816fe672..15517e3eb 100644
--- a/searx/engines/spotify.py
+++ b/searx/engines/spotify.py
@@ -42,9 +42,10 @@ def request(query, params):
     r = http_post(
         'https://accounts.spotify.com/api/token',
         data={'grant_type': 'client_credentials'},
-        headers={'Authorization': 'Basic ' + base64.b64encode(
-            "{}:{}".format(api_client_id, api_client_secret).encode()
-        ).decode()}
+        headers={
+            'Authorization': 'Basic '
+            + base64.b64encode("{}:{}".format(api_client_id, api_client_secret).encode()).decode()
+        },
     )
     j = loads(r.text)
     params['headers'] = {'Authorization': 'Bearer {}'.format(j.get('access_token'))}
@@ -63,18 +64,12 @@ def response(resp):
         if result['type'] == 'track':
             title = result['name']
             url = result['external_urls']['spotify']
-            content = '{} - {} - {}'.format(
-                result['artists'][0]['name'],
-                result['album']['name'],
-                result['name'])
+            content = '{} - {} - {}'.format(result['artists'][0]['name'], result['album']['name'], result['name'])
 
             embedded = embedded_url.format(audioid=result['id'])
 
             # append result
-            results.append({'url': url,
-                            'title': title,
-                            'embedded': embedded,
-                            'content': content})
+            results.append({'url': url, 'title': title, 'embedded': embedded, 'content': content})
 
     # return results
     return results
diff --git a/searx/engines/springer.py b/searx/engines/springer.py
index 246e59b44..512d71e5e 100644
--- a/searx/engines/springer.py
+++ b/searx/engines/springer.py
@@ -26,15 +26,11 @@ api_key = 'unset'
 
 base_url = 'https://api.springernature.com/metadata/json?'
 
+
 def request(query, params):
     if api_key == 'unset':
         raise SearxEngineAPIException('missing Springer-Nature API key')
-    args = urlencode({
-        'q' : query,
-        's' : nb_per_page * (params['pageno'] - 1),
-        'p' : nb_per_page,
-        'api_key' : api_key
-        })
+    args = urlencode({'q': query, 's': nb_per_page * (params['pageno'] - 1), 'p': nb_per_page, 'api_key': api_key})
     params['url'] = base_url + args
     logger.debug("query_url --> %s", params['url'])
     return params
@@ -50,21 +46,27 @@ def response(resp):
             content += "..."
         published = datetime.strptime(record['publicationDate'], '%Y-%m-%d')
 
-        metadata = [record[x] for x in [
-            'publicationName',
-            'identifier',
-            'contentType',
-        ] if record.get(x) is not None]
+        metadata = [
+            record[x]
+            for x in [
+                'publicationName',
+                'identifier',
+                'contentType',
+            ]
+            if record.get(x) is not None
+        ]
 
         metadata = ' / '.join(metadata)
         if record.get('startingPage') and record.get('endingPage') is not None:
             metadata += " (%(startingPage)s-%(endingPage)s)" % record
 
-        results.append({
-            'title': record['title'],
-            'url': record['url'][0]['value'].replace('http://', 'https://', 1),
-            'content' : content,
-            'publishedDate' : published,
-            'metadata' : metadata
-        })
+        results.append(
+            {
+                'title': record['title'],
+                'url': record['url'][0]['value'].replace('http://', 'https://', 1),
+                'content': content,
+                'publishedDate': published,
+                'metadata': metadata,
+            }
+        )
     return results
diff --git a/searx/engines/sqlite.py b/searx/engines/sqlite.py
index 43a85efbb..6de12f5fe 100644
--- a/searx/engines/sqlite.py
+++ b/searx/engines/sqlite.py
@@ -47,9 +47,9 @@ def search(query, params):
 
     query_params = {
         'query': query,
-        'wildcard':  r'%' + query.replace(' ', r'%') + r'%',
+        'wildcard': r'%' + query.replace(' ', r'%') + r'%',
         'limit': limit,
-        'offset': (params['pageno'] - 1) * limit
+        'offset': (params['pageno'] - 1) * limit,
     }
     query_to_run = query_str + ' LIMIT :limit OFFSET :offset'
 
@@ -59,7 +59,7 @@ def search(query, params):
         col_names = [cn[0] for cn in cur.description]
 
         for row in cur.fetchall():
-            item = dict( zip(col_names, map(str, row)) )
+            item = dict(zip(col_names, map(str, row)))
             item['template'] = result_template
             logger.debug("append result --> %s", item)
             results.append(item)
diff --git a/searx/engines/stackexchange.py b/searx/engines/stackexchange.py
index 34cba687c..99615b1a7 100644
--- a/searx/engines/stackexchange.py
+++ b/searx/engines/stackexchange.py
@@ -23,26 +23,30 @@ paging = True
 pagesize = 10
 
 api_site = 'stackoverflow'
-api_sort= 'activity'
+api_sort = 'activity'
 api_order = 'desc'
 
 # https://api.stackexchange.com/docs/advanced-search
 search_api = 'https://api.stackexchange.com/2.3/search/advanced?'
 
+
 def request(query, params):
 
-    args = urlencode({
-        'q' : query,
-        'page' : params['pageno'],
-        'pagesize' : pagesize,
-        'site' : api_site,
-        'sort' : api_sort,
-        'order': 'desc',
-        })
+    args = urlencode(
+        {
+            'q': query,
+            'page': params['pageno'],
+            'pagesize': pagesize,
+            'site': api_site,
+            'sort': api_sort,
+            'order': 'desc',
+        }
+    )
     params['url'] = search_api + args
 
     return params
 
+
 def response(resp):
 
     results = []
@@ -56,10 +60,12 @@ def response(resp):
             content += ' // is answered'
         content += " // score: %s" % result['score']
 
-        results.append({
-            'url': "https://%s.com/q/%s" % (api_site, result['question_id']),
-            'title':  html.unescape(result['title']),
-            'content': html.unescape(content),
-        })
+        results.append(
+            {
+                'url': "https://%s.com/q/%s" % (api_site, result['question_id']),
+                'title': html.unescape(result['title']),
+                'content': html.unescape(content),
+            }
+        )
 
     return results
diff --git a/searx/engines/startpage.py b/searx/engines/startpage.py
index e71310be6..65d90debe 100644
--- a/searx/engines/startpage.py
+++ b/searx/engines/startpage.py
@@ -101,7 +101,7 @@ def response(resp):
         # check if search result starts with something like: "2 Sep 2014 ... "
         if re.match(r"^([1-9]|[1-2][0-9]|3[0-1]) [A-Z][a-z]{2} [0-9]{4} \.\.\. ", content):
             date_pos = content.find('...') + 4
-            date_string = content[0:date_pos - 5]
+            date_string = content[0 : date_pos - 5]
             # fix content string
             content = content[date_pos:]
 
@@ -113,7 +113,7 @@ def response(resp):
         # check if search result starts with something like: "5 days ago ... "
         elif re.match(r"^[0-9]+ days? ago \.\.\. ", content):
             date_pos = content.find('...') + 4
-            date_string = content[0:date_pos - 5]
+            date_string = content[0 : date_pos - 5]
 
             # calculate datetime
             published_date = datetime.now() - timedelta(days=int(re.match(r'\d+', date_string).group()))
@@ -123,15 +123,10 @@ def response(resp):
 
         if published_date:
             # append result
-            results.append({'url': url,
-                            'title': title,
-                            'content': content,
-                            'publishedDate': published_date})
+            results.append({'url': url, 'title': title, 'content': content, 'publishedDate': published_date})
         else:
             # append result
-            results.append({'url': url,
-                            'title': title,
-                            'content': content})
+            results.append({'url': url, 'title': title, 'content': content})
 
     # return results
     return results
@@ -152,7 +147,7 @@ def _fetch_supported_languages(resp):
         'malayam': 'ml',
         'norsk': 'nb',
         'sinhalese': 'si',
-        'sudanese': 'su'
+        'sudanese': 'su',
     }
 
     # get the English name of every language known by babel
diff --git a/searx/engines/tokyotoshokan.py b/searx/engines/tokyotoshokan.py
index 0d62453a9..b01de38c1 100644
--- a/searx/engines/tokyotoshokan.py
+++ b/searx/engines/tokyotoshokan.py
@@ -56,11 +56,7 @@ def response(resp):
         name_row = rows[i]
 
         links = name_row.xpath('./td[@class="desc-top"]/a')
-        params = {
-            'template': 'torrent.html',
-            'url': links[-1].attrib.get('href'),
-            'title': extract_text(links[-1])
-        }
+        params = {'template': 'torrent.html', 'url': links[-1].attrib.get('href'), 'title': extract_text(links[-1])}
         # I have not yet seen any torrents without magnet links, but
         # it's better to be prepared to stumble upon one some day
         if len(links) == 2:
diff --git a/searx/engines/torznab.py b/searx/engines/torznab.py
index 960d1ee90..a48017c13 100644
--- a/searx/engines/torznab.py
+++ b/searx/engines/torznab.py
@@ -35,10 +35,12 @@ api_key = ''
 # https://newznab.readthedocs.io/en/latest/misc/api/#predefined-categories
 torznab_categories = []
 
-def init(engine_settings=None): # pylint: disable=unused-argument
+
+def init(engine_settings=None):  # pylint: disable=unused-argument
     if len(base_url) < 1:
         raise ValueError('missing torznab base_url')
 
+
 def request(query, params):
 
     search_url = base_url + '?t=search&q={search_query}'
@@ -48,13 +50,12 @@ def request(query, params):
         search_url += '&cat={torznab_categories}'
 
     params['url'] = search_url.format(
-        search_query = quote(query),
-        api_key = api_key,
-        torznab_categories = ",".join([str(x) for x in torznab_categories])
+        search_query=quote(query), api_key=api_key, torznab_categories=",".join([str(x) for x in torznab_categories])
     )
 
     return params
 
+
 def response(resp):
     results = []
 
@@ -103,8 +104,7 @@ def response(resp):
 
         result["publishedDate"] = None
         try:
-            result["publishedDate"] = datetime.strptime(
-                get_property(item, 'pubDate'), '%a, %d %b %Y %H:%M:%S %z')
+            result["publishedDate"] = datetime.strptime(get_property(item, 'pubDate'), '%a, %d %b %Y %H:%M:%S %z')
         except (ValueError, TypeError) as e:
             logger.debug("ignore exception (publishedDate): %s", e)
 
@@ -134,9 +134,7 @@ def get_property(item, property_name):
 def get_torznab_attr(item, attr_name):
     element = item.find(
         './/torznab:attr[@name="{attr_name}"]'.format(attr_name=attr_name),
-        {
-            'torznab': 'http://torznab.com/schemas/2015/feed'
-        }
+        {'torznab': 'http://torznab.com/schemas/2015/feed'},
     )
 
     if element is not None:
diff --git a/searx/engines/translated.py b/searx/engines/translated.py
index 8d67ca0bb..62ade49e2 100644
--- a/searx/engines/translated.py
+++ b/searx/engines/translated.py
@@ -28,24 +28,25 @@ def request(query, params):
         key_form = '&key=' + api_key
     else:
         key_form = ''
-    params['url'] = url.format(from_lang=params['from_lang'][1],
-                               to_lang=params['to_lang'][1],
-                               query=params['query'],
-                               key=key_form)
+    params['url'] = url.format(
+        from_lang=params['from_lang'][1], to_lang=params['to_lang'][1], query=params['query'], key=key_form
+    )
     return params
 
 
 def response(resp):
     results = []
-    results.append({
-        'url': web_url.format(
-            from_lang=resp.search_params['from_lang'][2],
-            to_lang=resp.search_params['to_lang'][2],
-            query=resp.search_params['query']),
-        'title': '[{0}-{1}] {2}'.format(
-            resp.search_params['from_lang'][1],
-            resp.search_params['to_lang'][1],
-            resp.search_params['query']),
-        'content': resp.json()['responseData']['translatedText']
-    })
+    results.append(
+        {
+            'url': web_url.format(
+                from_lang=resp.search_params['from_lang'][2],
+                to_lang=resp.search_params['to_lang'][2],
+                query=resp.search_params['query'],
+            ),
+            'title': '[{0}-{1}] {2}'.format(
+                resp.search_params['from_lang'][1], resp.search_params['to_lang'][1], resp.search_params['query']
+            ),
+            'content': resp.json()['responseData']['translatedText'],
+        }
+    )
     return results
diff --git a/searx/engines/unsplash.py b/searx/engines/unsplash.py
index 1445b4cec..1967fefd2 100644
--- a/searx/engines/unsplash.py
+++ b/searx/engines/unsplash.py
@@ -26,23 +26,13 @@ paging = True
 
 def clean_url(url):
     parsed = urlparse(url)
-    query = [(k, v) for (k, v)
-             in parse_qsl(parsed.query) if k not in ['ixid', 's']]
+    query = [(k, v) for (k, v) in parse_qsl(parsed.query) if k not in ['ixid', 's']]
 
-    return urlunparse((
-        parsed.scheme,
-        parsed.netloc,
-        parsed.path,
-        parsed.params,
-        urlencode(query),
-        parsed.fragment
-    ))
+    return urlunparse((parsed.scheme, parsed.netloc, parsed.path, parsed.params, urlencode(query), parsed.fragment))
 
 
 def request(query, params):
-    params['url'] = search_url + urlencode({
-        'query': query, 'page': params['pageno'], 'per_page': page_size
-    })
+    params['url'] = search_url + urlencode({'query': query, 'page': params['pageno'], 'per_page': page_size})
     logger.debug("query_url --> %s", params['url'])
     return params
 
@@ -53,13 +43,15 @@ def response(resp):
 
     if 'results' in json_data:
         for result in json_data['results']:
-            results.append({
-                'template': 'images.html',
-                'url': clean_url(result['links']['html']),
-                'thumbnail_src': clean_url(result['urls']['thumb']),
-                'img_src': clean_url(result['urls']['raw']),
-                'title': result.get('alt_description') or 'unknown',
-                'content': result.get('description') or ''
-            })
+            results.append(
+                {
+                    'template': 'images.html',
+                    'url': clean_url(result['links']['html']),
+                    'thumbnail_src': clean_url(result['urls']['thumb']),
+                    'img_src': clean_url(result['urls']['raw']),
+                    'title': result.get('alt_description') or 'unknown',
+                    'content': result.get('description') or '',
+                }
+            )
 
     return results
diff --git a/searx/engines/vimeo.py b/searx/engines/vimeo.py
index 824579256..52d201eac 100644
--- a/searx/engines/vimeo.py
+++ b/searx/engines/vimeo.py
@@ -25,15 +25,16 @@ paging = True
 base_url = 'https://vimeo.com/'
 search_url = base_url + '/search/page:{pageno}?{query}'
 
-embedded_url = '<iframe data-src="https://player.vimeo.com/video/{videoid}" ' +\
-    'width="540" height="304" frameborder="0" ' +\
-    'webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>'
+embedded_url = (
+    '<iframe data-src="https://player.vimeo.com/video/{videoid}" '
+    + 'width="540" height="304" frameborder="0" '
+    + 'webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>'
+)
 
 
 # do search-request
 def request(query, params):
-    params['url'] = search_url.format(pageno=params['pageno'],
-                                      query=urlencode({'q': query}))
+    params['url'] = search_url.format(pageno=params['pageno'], query=urlencode({'q': query}))
 
     return params
 
@@ -56,13 +57,17 @@ def response(resp):
         embedded = embedded_url.format(videoid=videoid)
 
         # append result
-        results.append({'url': url,
-                        'title': title,
-                        'content': '',
-                        'template': 'videos.html',
-                        'publishedDate': publishedDate,
-                        'embedded': embedded,
-                        'thumbnail': thumbnail})
+        results.append(
+            {
+                'url': url,
+                'title': title,
+                'content': '',
+                'template': 'videos.html',
+                'publishedDate': publishedDate,
+                'embedded': embedded,
+                'thumbnail': thumbnail,
+            }
+        )
 
     # return results
     return results
diff --git a/searx/engines/wikidata.py b/searx/engines/wikidata.py
index 59413499c..c8881d299 100644
--- a/searx/engines/wikidata.py
+++ b/searx/engines/wikidata.py
@@ -14,7 +14,10 @@ from searx.data import WIKIDATA_UNITS
 from searx.network import post, get
 from searx.utils import match_language, searx_useragent, get_string_replaces_function
 from searx.external_urls import get_external_url, get_earth_coordinates_url, area_to_osm_zoom
-from searx.engines.wikipedia import _fetch_supported_languages, supported_languages_url  # NOQA # pylint: disable=unused-import
+from searx.engines.wikipedia import (
+    _fetch_supported_languages,
+    supported_languages_url,
+)  # NOQA # pylint: disable=unused-import
 
 # about
 about = {
@@ -112,10 +115,7 @@ replace_http_by_https = get_string_replaces_function({'http:': 'https:'})
 
 def get_headers():
     # user agent: https://www.mediawiki.org/wiki/Wikidata_Query_Service/User_Manual#Query_limits
-    return {
-        'Accept': 'application/sparql-results+json',
-        'User-Agent': searx_useragent()
-    }
+    return {'Accept': 'application/sparql-results+json', 'User-Agent': searx_useragent()}
 
 
 def get_label_for_entity(entity_id, language):
@@ -211,9 +211,9 @@ def get_results(attribute_result, attributes, language):
                         results.append({'title': infobox_title, 'url': url})
                     # update the infobox_id with the wikipedia URL
                     # first the local wikipedia URL, and as fallback the english wikipedia URL
-                    if attribute_type == WDArticle\
-                       and ((attribute.language == 'en' and infobox_id_lang is None)
-                            or attribute.language != 'en'):
+                    if attribute_type == WDArticle and (
+                        (attribute.language == 'en' and infobox_id_lang is None) or attribute.language != 'en'
+                    ):
                         infobox_id_lang = attribute.language
                         infobox_id = url
             elif attribute_type == WDImageAttribute:
@@ -232,13 +232,11 @@ def get_results(attribute_result, attributes, language):
                 osm_zoom = area_to_osm_zoom(area) if area else 19
                 url = attribute.get_geo_url(attribute_result, osm_zoom=osm_zoom)
                 if url:
-                    infobox_urls.append({'title': attribute.get_label(language),
-                                         'url': url,
-                                         'entity': attribute.name})
+                    infobox_urls.append({'title': attribute.get_label(language), 'url': url, 'entity': attribute.name})
             else:
-                infobox_attributes.append({'label': attribute.get_label(language),
-                                           'value': value,
-                                           'entity': attribute.name})
+                infobox_attributes.append(
+                    {'label': attribute.get_label(language), 'value': value, 'entity': attribute.name}
+                )
 
     if infobox_id:
         infobox_id = replace_http_by_https(infobox_id)
@@ -246,22 +244,19 @@ def get_results(attribute_result, attributes, language):
     # add the wikidata URL at the end
     infobox_urls.append({'title': 'Wikidata', 'url': attribute_result['item']})
 
-    if img_src is None and len(infobox_attributes) == 0 and len(infobox_urls) == 1 and\
-       len(infobox_content) == 0:
-        results.append({
-            'url': infobox_urls[0]['url'],
-            'title': infobox_title,
-            'content': infobox_content
-        })
+    if img_src is None and len(infobox_attributes) == 0 and len(infobox_urls) == 1 and len(infobox_content) == 0:
+        results.append({'url': infobox_urls[0]['url'], 'title': infobox_title, 'content': infobox_content})
     else:
-        results.append({
-            'infobox': infobox_title,
-            'id': infobox_id,
-            'content': infobox_content,
-            'img_src': img_src,
-            'urls': infobox_urls,
-            'attributes': infobox_attributes
-        })
+        results.append(
+            {
+                'infobox': infobox_title,
+                'id': infobox_id,
+                'content': infobox_content,
+                'img_src': img_src,
+                'urls': infobox_urls,
+                'attributes': infobox_attributes,
+            }
+        )
     return results
 
 
@@ -271,13 +266,14 @@ def get_query(query, language):
     where = list(filter(lambda s: len(s) > 0, [a.get_where() for a in attributes]))
     wikibase_label = list(filter(lambda s: len(s) > 0, [a.get_wikibase_label() for a in attributes]))
     group_by = list(filter(lambda s: len(s) > 0, [a.get_group_by() for a in attributes]))
-    query = QUERY_TEMPLATE\
-        .replace('%QUERY%', sparql_string_escape(query))\
-        .replace('%SELECT%', ' '.join(select))\
-        .replace('%WHERE%', '\n  '.join(where))\
-        .replace('%WIKIBASE_LABELS%', '\n      '.join(wikibase_label))\
-        .replace('%GROUP_BY%', ' '.join(group_by))\
+    query = (
+        QUERY_TEMPLATE.replace('%QUERY%', sparql_string_escape(query))
+        .replace('%SELECT%', ' '.join(select))
+        .replace('%WHERE%', '\n  '.join(where))
+        .replace('%WIKIBASE_LABELS%', '\n      '.join(wikibase_label))
+        .replace('%GROUP_BY%', ' '.join(group_by))
         .replace('%LANGUAGE%', language)
+    )
     return query, attributes
 
 
@@ -303,90 +299,98 @@ def get_attributes(language):
         attributes.append(WDDateAttribute(name))
 
     # Dates
-    for p in ['P571',    # inception date
-              'P576',    # dissolution date
-              'P580',    # start date
-              'P582',    # end date
-              'P569',    # date of birth
-              'P570',    # date of death
-              'P619',    # date of spacecraft launch
-              'P620']:   # date of spacecraft landing
+    for p in [
+        'P571',  # inception date
+        'P576',  # dissolution date
+        'P580',  # start date
+        'P582',  # end date
+        'P569',  # date of birth
+        'P570',  # date of death
+        'P619',  # date of spacecraft launch
+        'P620',
+    ]:  # date of spacecraft landing
         add_date(p)
 
-    for p in ['P27',     # country of citizenship
-              'P495',    # country of origin
-              'P17',     # country
-              'P159']:   # headquarters location
+    for p in [
+        'P27',  # country of citizenship
+        'P495',  # country of origin
+        'P17',  # country
+        'P159',
+    ]:  # headquarters location
         add_label(p)
 
     # Places
-    for p in ['P36',     # capital
-              'P35',     # head of state
-              'P6',      # head of government
-              'P122',    # basic form of government
-              'P37']:    # official language
+    for p in [
+        'P36',  # capital
+        'P35',  # head of state
+        'P6',  # head of government
+        'P122',  # basic form of government
+        'P37',
+    ]:  # official language
         add_label(p)
 
-    add_value('P1082')   # population
+    add_value('P1082')  # population
     add_amount('P2046')  # area
-    add_amount('P281')   # postal code
-    add_label('P38')     # currency
+    add_amount('P281')  # postal code
+    add_label('P38')  # currency
     add_amount('P2048')  # heigth (building)
 
     # Media
-    for p in ['P400',    # platform (videogames, computing)
-              'P50',     # author
-              'P170',    # creator
-              'P57',     # director
-              'P175',    # performer
-              'P178',    # developer
-              'P162',    # producer
-              'P176',    # manufacturer
-              'P58',     # screenwriter
-              'P272',    # production company
-              'P264',    # record label
-              'P123',    # publisher
-              'P449',    # original network
-              'P750',    # distributed by
-              'P86']:    # composer
+    for p in [
+        'P400',  # platform (videogames, computing)
+        'P50',  # author
+        'P170',  # creator
+        'P57',  # director
+        'P175',  # performer
+        'P178',  # developer
+        'P162',  # producer
+        'P176',  # manufacturer
+        'P58',  # screenwriter
+        'P272',  # production company
+        'P264',  # record label
+        'P123',  # publisher
+        'P449',  # original network
+        'P750',  # distributed by
+        'P86',
+    ]:  # composer
         add_label(p)
 
-    add_date('P577')     # publication date
-    add_label('P136')    # genre (music, film, artistic...)
-    add_label('P364')    # original language
-    add_value('P212')    # ISBN-13
-    add_value('P957')    # ISBN-10
-    add_label('P275')    # copyright license
-    add_label('P277')    # programming language
-    add_value('P348')    # version
-    add_label('P840')    # narrative location
+    add_date('P577')  # publication date
+    add_label('P136')  # genre (music, film, artistic...)
+    add_label('P364')  # original language
+    add_value('P212')  # ISBN-13
+    add_value('P957')  # ISBN-10
+    add_label('P275')  # copyright license
+    add_label('P277')  # programming language
+    add_value('P348')  # version
+    add_label('P840')  # narrative location
 
     # Languages
-    add_value('P1098')   # number of speakers
-    add_label('P282')    # writing system
-    add_label('P1018')   # language regulatory body
-    add_value('P218')    # language code (ISO 639-1)
+    add_value('P1098')  # number of speakers
+    add_label('P282')  # writing system
+    add_label('P1018')  # language regulatory body
+    add_value('P218')  # language code (ISO 639-1)
 
     # Other
-    add_label('P169')    # ceo
-    add_label('P112')    # founded by
-    add_label('P1454')   # legal form (company, organization)
-    add_label('P137')    # operator (service, facility, ...)
-    add_label('P1029')   # crew members (tripulation)
-    add_label('P225')    # taxon name
-    add_value('P274')    # chemical formula
-    add_label('P1346')   # winner (sports, contests, ...)
-    add_value('P1120')   # number of deaths
-    add_value('P498')    # currency code (ISO 4217)
+    add_label('P169')  # ceo
+    add_label('P112')  # founded by
+    add_label('P1454')  # legal form (company, organization)
+    add_label('P137')  # operator (service, facility, ...)
+    add_label('P1029')  # crew members (tripulation)
+    add_label('P225')  # taxon name
+    add_value('P274')  # chemical formula
+    add_label('P1346')  # winner (sports, contests, ...)
+    add_value('P1120')  # number of deaths
+    add_value('P498')  # currency code (ISO 4217)
 
     # URL
-    add_url('P856', official=True)          # official website
+    add_url('P856', official=True)  # official website
     attributes.append(WDArticle(language))  # wikipedia (user language)
     if not language.startswith('en'):
         attributes.append(WDArticle('en'))  # wikipedia (english)
 
-    add_url('P1324')     # source code repository
-    add_url('P1581')     # blog
+    add_url('P1324')  # source code repository
+    add_url('P1581')  # blog
     add_url('P434', url_id='musicbrainz_artist')
     add_url('P435', url_id='musicbrainz_work')
     add_url('P436', url_id='musicbrainz_release_group')
@@ -402,11 +406,11 @@ def get_attributes(language):
     attributes.append(WDGeoAttribute('P625'))
 
     # Image
-    add_image('P15', priority=1, url_id='wikimedia_image')    # route map
-    add_image('P242', priority=2, url_id='wikimedia_image')   # locator map
-    add_image('P154', priority=3, url_id='wikimedia_image')   # logo
-    add_image('P18', priority=4, url_id='wikimedia_image')    # image
-    add_image('P41', priority=5, url_id='wikimedia_image')    # flag
+    add_image('P15', priority=1, url_id='wikimedia_image')  # route map
+    add_image('P242', priority=2, url_id='wikimedia_image')  # locator map
+    add_image('P154', priority=3, url_id='wikimedia_image')  # logo
+    add_image('P18', priority=4, url_id='wikimedia_image')  # image
+    add_image('P41', priority=5, url_id='wikimedia_image')  # flag
     add_image('P2716', priority=6, url_id='wikimedia_image')  # collage
     add_image('P2910', priority=7, url_id='wikimedia_image')  # icon
 
@@ -415,7 +419,7 @@ def get_attributes(language):
 
 class WDAttribute:
 
-    __slots__ = 'name',
+    __slots__ = ('name',)
 
     def __init__(self, name):
         self.name = name
@@ -443,14 +447,15 @@ class WDAttribute:
 
 
 class WDAmountAttribute(WDAttribute):
-
     def get_select(self):
         return '?{name} ?{name}Unit'.replace('{name}', self.name)
 
     def get_where(self):
         return """  OPTIONAL { ?item p:{name} ?{name}Node .
     ?{name}Node rdf:type wikibase:BestRank ; ps:{name} ?{name} .
-    OPTIONAL { ?{name}Node psv:{name}/wikibase:quantityUnit ?{name}Unit. } }""".replace('{name}', self.name)
+    OPTIONAL { ?{name}Node psv:{name}/wikibase:quantityUnit ?{name}Unit. } }""".replace(
+            '{name}', self.name
+        )
 
     def get_group_by(self):
         return self.get_select()
@@ -484,7 +489,9 @@ class WDArticle(WDAttribute):
         return """OPTIONAL { ?article{language} schema:about ?item ;
              schema:inLanguage "{language}" ;
              schema:isPartOf <https://{language}.wikipedia.org/> ;
-             schema:name ?articleName{language} . }""".replace('{language}', self.language)
+             schema:name ?articleName{language} . }""".replace(
+            '{language}', self.language
+        )
 
     def get_group_by(self):
         return self.get_select()
@@ -495,7 +502,6 @@ class WDArticle(WDAttribute):
 
 
 class WDLabelAttribute(WDAttribute):
-
     def get_select(self):
         return '(group_concat(distinct ?{name}Label;separator=", ") as ?{name}Labels)'.replace('{name}', self.name)
 
@@ -526,14 +532,13 @@ class WDURLAttribute(WDAttribute):
             value = value.split(',')[0]
             url_id = self.url_id
             if value.startswith(WDURLAttribute.HTTP_WIKIMEDIA_IMAGE):
-                value = value[len(WDURLAttribute.HTTP_WIKIMEDIA_IMAGE):]
+                value = value[len(WDURLAttribute.HTTP_WIKIMEDIA_IMAGE) :]
                 url_id = 'wikimedia_image'
             return get_external_url(url_id, value)
         return value
 
 
 class WDGeoAttribute(WDAttribute):
-
     def get_label(self, language):
         return "OpenStreetMap"
 
@@ -543,7 +548,9 @@ class WDGeoAttribute(WDAttribute):
     def get_where(self):
         return """OPTIONAL { ?item p:{name}/psv:{name} [
     wikibase:geoLatitude ?{name}Lat ;
-    wikibase:geoLongitude ?{name}Long ] }""".replace('{name}', self.name)
+    wikibase:geoLongitude ?{name}Long ] }""".replace(
+            '{name}', self.name
+        )
 
     def get_group_by(self):
         return self.get_select()
@@ -565,7 +572,7 @@ class WDGeoAttribute(WDAttribute):
 
 class WDImageAttribute(WDURLAttribute):
 
-    __slots__ = 'priority',
+    __slots__ = ('priority',)
 
     def __init__(self, name, url_id=None, priority=100):
         super().__init__(name, url_id)
@@ -573,7 +580,6 @@ class WDImageAttribute(WDURLAttribute):
 
 
 class WDDateAttribute(WDAttribute):
-
     def get_select(self):
         return '?{name} ?{name}timePrecision ?{name}timeZone ?{name}timeCalendar'.replace('{name}', self.name)
 
@@ -587,7 +593,9 @@ class WDDateAttribute(WDAttribute):
     wikibase:timePrecision ?{name}timePrecision ;
     wikibase:timeTimezone ?{name}timeZone ;
     wikibase:timeCalendarModel ?{name}timeCalendar ] . }
-    hint:Prior hint:rangeSafe true;""".replace('{name}', self.name)
+    hint:Prior hint:rangeSafe true;""".replace(
+            '{name}', self.name
+        )
 
     def get_group_by(self):
         return self.get_select()
@@ -619,11 +627,12 @@ class WDDateAttribute(WDAttribute):
     def format_13(self, value, locale):
         timestamp = isoparse(value)
         # precision: minute
-        return get_datetime_format(format, locale=locale) \
-            .replace("'", "") \
-            .replace('{0}', format_time(timestamp, 'full', tzinfo=None,
-                                        locale=locale)) \
+        return (
+            get_datetime_format(format, locale=locale)
+            .replace("'", "")
+            .replace('{0}', format_time(timestamp, 'full', tzinfo=None, locale=locale))
             .replace('{1}', format_date(timestamp, 'short', locale=locale))
+        )
 
     def format_14(self, value, locale):
         # precision: second.
@@ -644,7 +653,7 @@ class WDDateAttribute(WDAttribute):
         '11': ('format_11', 0),  # day
         '12': ('format_13', 0),  # hour (not supported by babel, display minute)
         '13': ('format_13', 0),  # minute
-        '14': ('format_14', 0)  # second
+        '14': ('format_14', 0),  # second
     }
 
     def get_str(self, result, language):
diff --git a/searx/engines/wikipedia.py b/searx/engines/wikipedia.py
index 5e34db9a7..cc806a8de 100644
--- a/searx/engines/wikipedia.py
+++ b/searx/engines/wikipedia.py
@@ -39,8 +39,7 @@ def request(query, params):
         query = query.title()
 
     language = url_lang(params['language'])
-    params['url'] = search_url.format(title=quote(query),
-                                      language=language)
+    params['url'] = search_url.format(title=quote(query), language=language)
 
     if params['language'].lower() in language_variants.get(language, []):
         params['headers']['Accept-Language'] = params['language'].lower()
@@ -63,8 +62,10 @@ def response(resp):
         except:
             pass
         else:
-            if api_result['type'] == 'https://mediawiki.org/wiki/HyperSwitch/errors/bad_request' \
-               and api_result['detail'] == 'title-invalid-characters':
+            if (
+                api_result['type'] == 'https://mediawiki.org/wiki/HyperSwitch/errors/bad_request'
+                and api_result['detail'] == 'title-invalid-characters'
+            ):
                 return []
 
     raise_for_httperror(resp)
@@ -81,11 +82,15 @@ def response(resp):
 
     results.append({'url': wikipedia_link, 'title': title})
 
-    results.append({'infobox': title,
-                    'id': wikipedia_link,
-                    'content': api_result.get('extract', ''),
-                    'img_src': api_result.get('thumbnail', {}).get('source'),
-                    'urls': [{'title': 'Wikipedia', 'url': wikipedia_link}]})
+    results.append(
+        {
+            'infobox': title,
+            'id': wikipedia_link,
+            'content': api_result.get('extract', ''),
+            'img_src': api_result.get('thumbnail', {}).get('source'),
+            'urls': [{'title': 'Wikipedia', 'url': wikipedia_link}],
+        }
+    )
 
     return results
 
diff --git a/searx/engines/wolframalpha_api.py b/searx/engines/wolframalpha_api.py
index 9c84e2809..1c882c582 100644
--- a/searx/engines/wolframalpha_api.py
+++ b/searx/engines/wolframalpha_api.py
@@ -36,8 +36,7 @@ img_alt_xpath = './@alt'
 
 # pods to display as image in infobox
 # this pods do return a plaintext, but they look better and are more useful as images
-image_pods = {'VisualRepresentation',
-              'Illustration'}
+image_pods = {'VisualRepresentation', 'Illustration'}
 
 
 # do search-request
@@ -50,15 +49,17 @@ def request(query, params):
 
 # replace private user area characters to make text legible
 def replace_pua_chars(text):
-    pua_chars = {'\uf522': '\u2192',  # rigth arrow
-                 '\uf7b1': '\u2115',  # set of natural numbers
-                 '\uf7b4': '\u211a',  # set of rational numbers
-                 '\uf7b5': '\u211d',  # set of real numbers
-                 '\uf7bd': '\u2124',  # set of integer numbers
-                 '\uf74c': 'd',       # differential
-                 '\uf74d': '\u212f',  # euler's number
-                 '\uf74e': 'i',       # imaginary number
-                 '\uf7d9': '='}       # equals sign
+    pua_chars = {
+        '\uf522': '\u2192',  # rigth arrow
+        '\uf7b1': '\u2115',  # set of natural numbers
+        '\uf7b4': '\u211a',  # set of rational numbers
+        '\uf7b5': '\u211d',  # set of real numbers
+        '\uf7bd': '\u2124',  # set of integer numbers
+        '\uf74c': 'd',  # differential
+        '\uf74d': '\u212f',  # euler's number
+        '\uf74e': 'i',  # imaginary number
+        '\uf7d9': '=',
+    }  # equals sign
 
     for k, v in pua_chars.items():
         text = text.replace(k, v)
@@ -112,9 +113,12 @@ def response(resp):
                 result_chunks.append({'label': pod_title, 'value': content})
 
             elif image:
-                result_chunks.append({'label': pod_title,
-                                      'image': {'src': image[0].xpath(img_src_xpath)[0],
-                                                'alt': image[0].xpath(img_alt_xpath)[0]}})
+                result_chunks.append(
+                    {
+                        'label': pod_title,
+                        'image': {'src': image[0].xpath(img_src_xpath)[0], 'alt': image[0].xpath(img_alt_xpath)[0]},
+                    }
+                )
 
     if not result_chunks:
         return []
@@ -122,13 +126,15 @@ def response(resp):
     title = "Wolfram|Alpha (%s)" % infobox_title
 
     # append infobox
-    results.append({'infobox': infobox_title,
-                    'attributes': result_chunks,
-                    'urls': [{'title': 'Wolfram|Alpha', 'url': resp.request.headers['Referer']}]})
+    results.append(
+        {
+            'infobox': infobox_title,
+            'attributes': result_chunks,
+            'urls': [{'title': 'Wolfram|Alpha', 'url': resp.request.headers['Referer']}],
+        }
+    )
 
     # append link to site
-    results.append({'url': resp.request.headers['Referer'],
-                    'title': title,
-                    'content': result_content})
+    results.append({'url': resp.request.headers['Referer'], 'title': title, 'content': result_content})
 
     return results
diff --git a/searx/engines/wolframalpha_noapi.py b/searx/engines/wolframalpha_noapi.py
index 1f2cfa4e6..bad25602a 100644
--- a/searx/engines/wolframalpha_noapi.py
+++ b/searx/engines/wolframalpha_noapi.py
@@ -22,30 +22,29 @@ about = {
 # search-url
 url = 'https://www.wolframalpha.com/'
 
-search_url = url + 'input/json.jsp'\
-    '?async=false'\
-    '&banners=raw'\
-    '&debuggingdata=false'\
-    '&format=image,plaintext,imagemap,minput,moutput'\
-    '&formattimeout=2'\
-    '&{query}'\
-    '&output=JSON'\
-    '&parsetimeout=2'\
-    '&proxycode={token}'\
-    '&scantimeout=0.5'\
-    '&sponsorcategories=true'\
+search_url = (
+    url + 'input/json.jsp'
+    '?async=false'
+    '&banners=raw'
+    '&debuggingdata=false'
+    '&format=image,plaintext,imagemap,minput,moutput'
+    '&formattimeout=2'
+    '&{query}'
+    '&output=JSON'
+    '&parsetimeout=2'
+    '&proxycode={token}'
+    '&scantimeout=0.5'
+    '&sponsorcategories=true'
     '&statemethod=deploybutton'
+)
 
 referer_url = url + 'input/?{query}'
 
-token = {'value': '',
-         'last_updated': None}
+token = {'value': '', 'last_updated': None}
 
 # pods to display as image in infobox
 # this pods do return a plaintext, but they look better and are more useful as images
-image_pods = {'VisualRepresentation',
-              'Illustration',
-              'Symbol'}
+image_pods = {'VisualRepresentation', 'Illustration', 'Symbol'}
 
 
 # seems, wolframalpha resets its token in every hour
@@ -115,12 +114,20 @@ def response(resp):
     if not result_chunks:
         return []
 
-    results.append({'infobox': infobox_title,
-                    'attributes': result_chunks,
-                    'urls': [{'title': 'Wolfram|Alpha', 'url': resp.request.headers['Referer']}]})
-
-    results.append({'url': resp.request.headers['Referer'],
-                    'title': 'Wolfram|Alpha (' + infobox_title + ')',
-                    'content': result_content})
+    results.append(
+        {
+            'infobox': infobox_title,
+            'attributes': result_chunks,
+            'urls': [{'title': 'Wolfram|Alpha', 'url': resp.request.headers['Referer']}],
+        }
+    )
+
+    results.append(
+        {
+            'url': resp.request.headers['Referer'],
+            'title': 'Wolfram|Alpha (' + infobox_title + ')',
+            'content': result_content,
+        }
+    )
 
     return results
diff --git a/searx/engines/wordnik.py b/searx/engines/wordnik.py
index 0c3785cfb..21eaeccc3 100644
--- a/searx/engines/wordnik.py
+++ b/searx/engines/wordnik.py
@@ -48,7 +48,7 @@ def response(resp):
             def_abbr = extract_text(def_item.xpath('.//abbr')).strip()
             def_text = extract_text(def_item).strip()
             if def_abbr:
-                def_text = def_text[len(def_abbr):].strip()
+                def_text = def_text[len(def_abbr) :].strip()
             src_defs.append((def_abbr, def_text))
 
         definitions.append((src_text, src_defs))
@@ -66,9 +66,11 @@ def response(resp):
             infobox += f"<li><i>{def_abbr}</i> {def_text}</li>"
         infobox += "</ul>"
 
-    results.append({
-        'infobox': word,
-        'content': infobox,
-    })
+    results.append(
+        {
+            'infobox': word,
+            'content': infobox,
+        }
+    )
 
     return results
diff --git a/searx/engines/www1x.py b/searx/engines/www1x.py
index 96b8d680c..f6b82944d 100644
--- a/searx/engines/www1x.py
+++ b/searx/engines/www1x.py
@@ -46,12 +46,16 @@ def response(resp):
         thumbnail_src = urljoin(gallery_url, eval_xpath_getindex(link, './/img', 0).attrib['src'])
 
         # append result
-        results.append({'url': url,
-                        'title': title,
-                        'img_src': thumbnail_src,
-                        'content': '',
-                        'thumbnail_src': thumbnail_src,
-                        'template': 'images.html'})
+        results.append(
+            {
+                'url': url,
+                'title': title,
+                'img_src': thumbnail_src,
+                'content': '',
+                'thumbnail_src': thumbnail_src,
+                'template': 'images.html',
+            }
+        )
 
     # return results
     return results
diff --git a/searx/engines/xpath.py b/searx/engines/xpath.py
index 08677b708..2737bf94a 100644
--- a/searx/engines/xpath.py
+++ b/searx/engines/xpath.py
@@ -56,7 +56,7 @@ Replacements are:
 
 """
 
-lang_all='en'
+lang_all = 'en'
 '''Replacement ``{lang}`` in :py:obj:`search_url` if language ``all`` is
 selected.
 '''
@@ -110,9 +110,9 @@ requested by the user, the URL paramter is an empty string.  The
 
 time_range_map = {
     'day': 24,
-    'week': 24*7,
-    'month': 24*30,
-    'year': 24*365,
+    'week': 24 * 7,
+    'month': 24 * 30,
+    'year': 24 * 365,
 }
 '''Maps time range value from user to ``{time_range_val}`` in
 :py:obj:`time_range_url`.
@@ -129,11 +129,7 @@ time_range_map = {
 safe_search_support = False
 '''Engine supports safe-search.'''
 
-safe_search_map = {
-    0: '&filter=none',
-    1: '&filter=moderate',
-    2: '&filter=strict'
-}
+safe_search_map = {0: '&filter=none', 1: '&filter=moderate', 2: '&filter=strict'}
 '''Maps safe-search value to ``{safe_search}`` in :py:obj:`search_url`.
 
 .. code:: yaml
@@ -146,10 +142,9 @@ safe_search_map = {
 
 '''
 
-def request(query, params):
-    '''Build request parameters (see :ref:`engine request`).
 
-    '''
+def request(query, params):
+    '''Build request parameters (see :ref:`engine request`).'''
     lang = lang_all
     if params['language'] != 'all':
         lang = params['language'][:2]
@@ -167,8 +162,8 @@ def request(query, params):
         'query': urlencode({'q': query})[2:],
         'lang': lang,
         'pageno': (params['pageno'] - 1) * page_size + first_page_num,
-        'time_range' : time_range,
-        'safe_search' : safe_search,
+        'time_range': time_range,
+        'safe_search': safe_search,
     }
 
     params['url'] = search_url.format(**fargs)
@@ -176,10 +171,9 @@ def request(query, params):
 
     return params
 
-def response(resp):
-    '''Scrap *results* from the response (see :ref:`engine results`).
 
-    '''
+def response(resp):
+    '''Scrap *results* from the response (see :ref:`engine results`).'''
     results = []
     dom = html.fromstring(resp.text)
     is_onion = 'onions' in categories
@@ -200,10 +194,7 @@ def response(resp):
 
             # add alternative cached url if available
             if cached_xpath:
-                tmp_result['cached_url'] = (
-                    cached_url
-                    + extract_text(eval_xpath_list(result, cached_xpath, min_len=1))
-                )
+                tmp_result['cached_url'] = cached_url + extract_text(eval_xpath_list(result, cached_xpath, min_len=1))
 
             if is_onion:
                 tmp_result['is_onion'] = True
@@ -213,31 +204,27 @@ def response(resp):
     else:
         if cached_xpath:
             for url, title, content, cached in zip(
-                (extract_url(x, search_url) for
-                 x in eval_xpath_list(dom, url_xpath)),
+                (extract_url(x, search_url) for x in eval_xpath_list(dom, url_xpath)),
                 map(extract_text, eval_xpath_list(dom, title_xpath)),
                 map(extract_text, eval_xpath_list(dom, content_xpath)),
-                map(extract_text, eval_xpath_list(dom, cached_xpath))
+                map(extract_text, eval_xpath_list(dom, cached_xpath)),
             ):
-                results.append({
-                    'url': url,
-                    'title': title,
-                    'content': content,
-                    'cached_url': cached_url + cached, 'is_onion': is_onion
-                })
+                results.append(
+                    {
+                        'url': url,
+                        'title': title,
+                        'content': content,
+                        'cached_url': cached_url + cached,
+                        'is_onion': is_onion,
+                    }
+                )
         else:
             for url, title, content in zip(
-                (extract_url(x, search_url) for
-                 x in eval_xpath_list(dom, url_xpath)),
+                (extract_url(x, search_url) for x in eval_xpath_list(dom, url_xpath)),
                 map(extract_text, eval_xpath_list(dom, title_xpath)),
-                map(extract_text, eval_xpath_list(dom, content_xpath))
+                map(extract_text, eval_xpath_list(dom, content_xpath)),
             ):
-                results.append({
-                    'url': url,
-                    'title': title,
-                    'content': content,
-                    'is_onion': is_onion
-                })
+                results.append({'url': url, 'title': title, 'content': content, 'is_onion': is_onion})
 
     if suggestion_xpath:
         for suggestion in eval_xpath(dom, suggestion_xpath):
diff --git a/searx/engines/yacy.py b/searx/engines/yacy.py
index fbd99c47b..12e7305db 100644
--- a/searx/engines/yacy.py
+++ b/searx/engines/yacy.py
@@ -30,18 +30,16 @@ http_digest_auth_pass = ""
 
 # search-url
 base_url = 'http://localhost:8090'
-search_url = '/yacysearch.json?{query}'\
-             '&startRecord={offset}'\
-             '&maximumRecords={limit}'\
-             '&contentdom={search_type}'\
-             '&resource=global'
+search_url = (
+    '/yacysearch.json?{query}'
+    '&startRecord={offset}'
+    '&maximumRecords={limit}'
+    '&contentdom={search_type}'
+    '&resource=global'
+)
 
 # yacy specific type-definitions
-search_types = {'general': 'text',
-                'images': 'image',
-                'files': 'app',
-                'music': 'audio',
-                'videos': 'video'}
+search_types = {'general': 'text', 'images': 'image', 'files': 'app', 'music': 'audio', 'videos': 'video'}
 
 
 # do search-request
@@ -49,11 +47,9 @@ def request(query, params):
     offset = (params['pageno'] - 1) * number_of_results
     search_type = search_types.get(params.get('category'), '0')
 
-    params['url'] = base_url +\
-        search_url.format(query=urlencode({'query': query}),
-                          offset=offset,
-                          limit=number_of_results,
-                          search_type=search_type)
+    params['url'] = base_url + search_url.format(
+        query=urlencode({'query': query}), offset=offset, limit=number_of_results, search_type=search_type
+    )
 
     if http_digest_auth_user and http_digest_auth_pass:
         params['auth'] = DigestAuth(http_digest_auth_user, http_digest_auth_pass)
@@ -93,21 +89,29 @@ def response(resp):
                 continue
 
             # append result
-            results.append({'url': result_url,
-                            'title': result['title'],
-                            'content': '',
-                            'img_src': result['image'],
-                            'template': 'images.html'})
+            results.append(
+                {
+                    'url': result_url,
+                    'title': result['title'],
+                    'content': '',
+                    'img_src': result['image'],
+                    'template': 'images.html',
+                }
+            )
 
         # parse general results
         else:
             publishedDate = parser.parse(result['pubDate'])
 
             # append result
-            results.append({'url': result['link'],
-                            'title': result['title'],
-                            'content': html_to_text(result['description']),
-                            'publishedDate': publishedDate})
+            results.append(
+                {
+                    'url': result['link'],
+                    'title': result['title'],
+                    'content': html_to_text(result['description']),
+                    'publishedDate': publishedDate,
+                }
+            )
 
         # TODO parse video, audio and file results
 
diff --git a/searx/engines/yahoo.py b/searx/engines/yahoo.py
index bd6e6721c..08bde6665 100644
--- a/searx/engines/yahoo.py
+++ b/searx/engines/yahoo.py
@@ -50,59 +50,59 @@ language_aliases = {
 }
 
 lang2domain = {
-    'zh_chs' : 'hk.search.yahoo.com',
-    'zh_cht' : 'tw.search.yahoo.com',
-    'en'     : 'search.yahoo.com',
-
-    'bg'     : 'search.yahoo.com',
-    'cs'     : 'search.yahoo.com',
-    'da'     : 'search.yahoo.com',
-    'el'     : 'search.yahoo.com',
-    'et'     : 'search.yahoo.com',
-    'he'     : 'search.yahoo.com',
-    'hr'     : 'search.yahoo.com',
-    'ja'     : 'search.yahoo.com',
-    'ko'     : 'search.yahoo.com',
-    'sk'     : 'search.yahoo.com',
-    'sl'     : 'search.yahoo.com',
-
+    'zh_chs': 'hk.search.yahoo.com',
+    'zh_cht': 'tw.search.yahoo.com',
+    'en': 'search.yahoo.com',
+    'bg': 'search.yahoo.com',
+    'cs': 'search.yahoo.com',
+    'da': 'search.yahoo.com',
+    'el': 'search.yahoo.com',
+    'et': 'search.yahoo.com',
+    'he': 'search.yahoo.com',
+    'hr': 'search.yahoo.com',
+    'ja': 'search.yahoo.com',
+    'ko': 'search.yahoo.com',
+    'sk': 'search.yahoo.com',
+    'sl': 'search.yahoo.com',
 }
 """Map language to domain"""
 
+
 def _get_language(params):
 
     lang = language_aliases.get(params['language'])
     if lang is None:
-        lang = match_language(
-            params['language'], supported_languages, language_aliases
-        )
+        lang = match_language(params['language'], supported_languages, language_aliases)
     lang = lang.split('-')[0]
-    logger.debug("params['language']: %s --> %s" , params['language'], lang)
+    logger.debug("params['language']: %s --> %s", params['language'], lang)
     return lang
 
+
 def request(query, params):
     """build request"""
     offset = (params['pageno'] - 1) * 7 + 1
-    lang  =  _get_language(params)
-    age, btf = time_range_dict.get(
-        params['time_range'], ('', ''))
-
-    args = urlencode({
-        'p' : query,
-        'ei' : 'UTF-8',
-        'fl' : 1,
-        'vl' : 'lang_' + lang,
-        'btf' : btf,
-        'fr2' : 'time',
-        'age' : age,
-        'b' : offset,
-        'xargs' :0
-    })
+    lang = _get_language(params)
+    age, btf = time_range_dict.get(params['time_range'], ('', ''))
+
+    args = urlencode(
+        {
+            'p': query,
+            'ei': 'UTF-8',
+            'fl': 1,
+            'vl': 'lang_' + lang,
+            'btf': btf,
+            'fr2': 'time',
+            'age': age,
+            'b': offset,
+            'xargs': 0,
+        }
+    )
 
     domain = lang2domain.get(lang, '%s.search.yahoo.com' % lang)
     params['url'] = 'https://%s/search?%s' % (domain, args)
     return params
 
+
 def parse_url(url_string):
     """remove yahoo-specific tracking-url"""
 
@@ -121,6 +121,7 @@ def parse_url(url_string):
     end = min(endpositions)
     return unquote(url_string[start:end])
 
+
 def response(resp):
     """parse response"""
 
@@ -140,18 +141,12 @@ def response(resp):
         offset = len(extract_text(title.xpath('span')))
         title = extract_text(title)[offset:]
 
-        content = eval_xpath_getindex(
-            result, './/div[contains(@class, "compText")]', 0, default=''
-        )
+        content = eval_xpath_getindex(result, './/div[contains(@class, "compText")]', 0, default='')
         if content:
             content = extract_text(content)
 
         # append result
-        results.append({
-            'url': url,
-            'title': title,
-            'content': content
-        })
+        results.append({'url': url, 'title': title, 'content': content})
 
     for suggestion in eval_xpath_list(dom, '//div[contains(@class, "AlsoTry")]//table//a'):
         # append suggestion
@@ -167,6 +162,6 @@ def _fetch_supported_languages(resp):
     offset = len('lang_')
 
     for val in eval_xpath_list(dom, '//div[contains(@class, "lang-item")]/input/@value'):
-        supported_languages.append( val[offset:] )
+        supported_languages.append(val[offset:])
 
     return supported_languages
diff --git a/searx/engines/yahoo_news.py b/searx/engines/yahoo_news.py
index ec07cd408..06f090f74 100644
--- a/searx/engines/yahoo_news.py
+++ b/searx/engines/yahoo_news.py
@@ -39,36 +39,31 @@ paging = True
 categories = ['news']
 
 # search-url
-search_url = (
-    'https://news.search.yahoo.com/search'
-    '?{query}&b={offset}'
-    )
+search_url = 'https://news.search.yahoo.com/search' '?{query}&b={offset}'
 
 AGO_RE = re.compile(r'([0-9]+)\s*(year|month|week|day|minute|hour)')
 AGO_TIMEDELTA = {
-  'minute': timedelta(minutes=1),
-  'hour': timedelta(hours=1),
-  'day': timedelta(days=1),
-  'week': timedelta(days=7),
-  'month': timedelta(days=30),
-  'year': timedelta(days=365),
+    'minute': timedelta(minutes=1),
+    'hour': timedelta(hours=1),
+    'day': timedelta(days=1),
+    'week': timedelta(days=7),
+    'month': timedelta(days=30),
+    'year': timedelta(days=365),
 }
 
+
 def request(query, params):
     offset = (params['pageno'] - 1) * 10 + 1
 
-    params['url'] = search_url.format(
-        offset = offset,
-        query = urlencode({'p': query})
-    )
+    params['url'] = search_url.format(offset=offset, query=urlencode({'p': query}))
     logger.debug("query_url --> %s", params['url'])
     return params
 
+
 def response(resp):
     results = []
     dom = html.fromstring(resp.text)
 
-
     # parse results
     for result in eval_xpath_list(dom, '//ol[contains(@class,"searchCenterMiddle")]//li'):
 
@@ -80,12 +75,7 @@ def response(resp):
         content = extract_text(result.xpath('.//p'))
         img_src = eval_xpath_getindex(result, './/img/@data-src', 0, None)
 
-        item = {
-            'url': url,
-            'title': title,
-            'content': content,
-            'img_src' : img_src
-        }
+        item = {'url': url, 'title': title, 'content': content, 'img_src': img_src}
 
         pub_date = extract_text(result.xpath('.//span[contains(@class,"s-time")]'))
         ago = AGO_RE.search(pub_date)
diff --git a/searx/engines/youtube_api.py b/searx/engines/youtube_api.py
index ed27db07b..52db45960 100644
--- a/searx/engines/youtube_api.py
+++ b/searx/engines/youtube_api.py
@@ -27,17 +27,18 @@ api_key = None
 base_url = 'https://www.googleapis.com/youtube/v3/search'
 search_url = base_url + '?part=snippet&{query}&maxResults=20&key={api_key}'
 
-embedded_url = '<iframe width="540" height="304" ' +\
-    'data-src="https://www.youtube-nocookie.com/embed/{videoid}" ' +\
-    'frameborder="0" allowfullscreen></iframe>'
+embedded_url = (
+    '<iframe width="540" height="304" '
+    + 'data-src="https://www.youtube-nocookie.com/embed/{videoid}" '
+    + 'frameborder="0" allowfullscreen></iframe>'
+)
 
 base_youtube_url = 'https://www.youtube.com/watch?v='
 
 
 # do search-request
 def request(query, params):
-    params['url'] = search_url.format(query=urlencode({'q': query}),
-                                      api_key=api_key)
+    params['url'] = search_url.format(query=urlencode({'q': query}), api_key=api_key)
 
     # add language tag if specified
     if params['language'] != 'all':
@@ -79,13 +80,17 @@ def response(resp):
         embedded = embedded_url.format(videoid=videoid)
 
         # append result
-        results.append({'url': url,
-                        'title': title,
-                        'content': content,
-                        'template': 'videos.html',
-                        'publishedDate': publishedDate,
-                        'embedded': embedded,
-                        'thumbnail': thumbnail})
+        results.append(
+            {
+                'url': url,
+                'title': title,
+                'content': content,
+                'template': 'videos.html',
+                'publishedDate': publishedDate,
+                'embedded': embedded,
+                'thumbnail': thumbnail,
+            }
+        )
 
     # return results
     return results
diff --git a/searx/engines/youtube_noapi.py b/searx/engines/youtube_noapi.py
index 68b75bc72..239830cc7 100644
--- a/searx/engines/youtube_noapi.py
+++ b/searx/engines/youtube_noapi.py
@@ -30,14 +30,13 @@ search_url = base_url + '?search_query={query}&page={page}'
 time_range_url = '&sp=EgII{time_range}%253D%253D'
 # the key seems to be constant
 next_page_url = 'https://www.youtube.com/youtubei/v1/search?key=AIzaSyAO_FJ2SlqU8Q4STEHLGCilw_Y9_11qcW8'
-time_range_dict = {'day': 'Ag',
-                   'week': 'Aw',
-                   'month': 'BA',
-                   'year': 'BQ'}
+time_range_dict = {'day': 'Ag', 'week': 'Aw', 'month': 'BA', 'year': 'BQ'}
 
-embedded_url = '<iframe width="540" height="304" ' +\
-    'data-src="https://www.youtube-nocookie.com/embed/{videoid}" ' +\
-    'frameborder="0" allowfullscreen></iframe>'
+embedded_url = (
+    '<iframe width="540" height="304" '
+    + 'data-src="https://www.youtube-nocookie.com/embed/{videoid}" '
+    + 'frameborder="0" allowfullscreen></iframe>'
+)
 
 base_youtube_url = 'https://www.youtube.com/watch?v='
 
@@ -51,10 +50,12 @@ def request(query, params):
     else:
         params['url'] = next_page_url
         params['method'] = 'POST'
-        params['data'] = dumps({
-            'context': {"client": {"clientName": "WEB", "clientVersion": "2.20210310.12.01"}},
-            'continuation': params['engine_data']['next_page_token'],
-        })
+        params['data'] = dumps(
+            {
+                'context': {"client": {"clientName": "WEB", "clientVersion": "2.20210310.12.01"}},
+                'continuation': params['engine_data']['next_page_token'],
+            }
+        )
         params['headers']['Content-Type'] = 'application/json'
 
     params['headers']['Cookie'] = "CONSENT=YES+cb.%s-17-p0.en+F+941;" % datetime.now().strftime("%Y%m%d")
@@ -71,34 +72,42 @@ def response(resp):
 def parse_next_page_response(response_text):
     results = []
     result_json = loads(response_text)
-    for section in (result_json['onResponseReceivedCommands'][0]
-                    .get('appendContinuationItemsAction')['continuationItems'][0]
-                    .get('itemSectionRenderer')['contents']):
+    for section in (
+        result_json['onResponseReceivedCommands'][0]
+        .get('appendContinuationItemsAction')['continuationItems'][0]
+        .get('itemSectionRenderer')['contents']
+    ):
         if 'videoRenderer' not in section:
             continue
         section = section['videoRenderer']
         content = "-"
         if 'descriptionSnippet' in section:
             content = ' '.join(x['text'] for x in section['descriptionSnippet']['runs'])
-        results.append({
-            'url': base_youtube_url + section['videoId'],
-            'title': ' '.join(x['text'] for x in section['title']['runs']),
-            'content': content,
-            'author': section['ownerText']['runs'][0]['text'],
-            'length': section['lengthText']['simpleText'],
-            'template': 'videos.html',
-            'embedded': embedded_url.format(videoid=section['videoId']),
-            'thumbnail': section['thumbnail']['thumbnails'][-1]['url'],
-        })
+        results.append(
+            {
+                'url': base_youtube_url + section['videoId'],
+                'title': ' '.join(x['text'] for x in section['title']['runs']),
+                'content': content,
+                'author': section['ownerText']['runs'][0]['text'],
+                'length': section['lengthText']['simpleText'],
+                'template': 'videos.html',
+                'embedded': embedded_url.format(videoid=section['videoId']),
+                'thumbnail': section['thumbnail']['thumbnails'][-1]['url'],
+            }
+        )
     try:
-        token = result_json['onResponseReceivedCommands'][0]\
-            .get('appendContinuationItemsAction')['continuationItems'][1]\
-            .get('continuationItemRenderer')['continuationEndpoint']\
+        token = (
+            result_json['onResponseReceivedCommands'][0]
+            .get('appendContinuationItemsAction')['continuationItems'][1]
+            .get('continuationItemRenderer')['continuationEndpoint']
             .get('continuationCommand')['token']
-        results.append({
-            "engine_data": token,
-            "key": "next_page_token",
-        })
+        )
+        results.append(
+            {
+                "engine_data": token,
+                "key": "next_page_token",
+            }
+        )
     except:
         pass
 
@@ -107,26 +116,32 @@ def parse_next_page_response(response_text):
 
 def parse_first_page_response(response_text):
     results = []
-    results_data = response_text[response_text.find('ytInitialData'):]
-    results_data = results_data[results_data.find('{'):results_data.find(';</script>')]
+    results_data = response_text[response_text.find('ytInitialData') :]
+    results_data = results_data[results_data.find('{') : results_data.find(';</script>')]
     results_json = loads(results_data) if results_data else {}
-    sections = results_json.get('contents', {})\
-                           .get('twoColumnSearchResultsRenderer', {})\
-                           .get('primaryContents', {})\
-                           .get('sectionListRenderer', {})\
-                           .get('contents', [])
+    sections = (
+        results_json.get('contents', {})
+        .get('twoColumnSearchResultsRenderer', {})
+        .get('primaryContents', {})
+        .get('sectionListRenderer', {})
+        .get('contents', [])
+    )
 
     for section in sections:
         if "continuationItemRenderer" in section:
-            next_page_token = section["continuationItemRenderer"]\
-                .get("continuationEndpoint", {})\
-                .get("continuationCommand", {})\
+            next_page_token = (
+                section["continuationItemRenderer"]
+                .get("continuationEndpoint", {})
+                .get("continuationCommand", {})
                 .get("token", "")
+            )
             if next_page_token:
-                results.append({
-                    "engine_data": next_page_token,
-                    "key": "next_page_token",
-                })
+                results.append(
+                    {
+                        "engine_data": next_page_token,
+                        "key": "next_page_token",
+                    }
+                )
         for video_container in section.get('itemSectionRenderer', {}).get('contents', []):
             video = video_container.get('videoRenderer', {})
             videoid = video.get('videoId')
@@ -140,14 +155,18 @@ def parse_first_page_response(response_text):
                 length = get_text_from_json(video.get('lengthText', {}))
 
                 # append result
-                results.append({'url': url,
-                                'title': title,
-                                'content': content,
-                                'author': author,
-                                'length': length,
-                                'template': 'videos.html',
-                                'embedded': embedded,
-                                'thumbnail': thumbnail})
+                results.append(
+                    {
+                        'url': url,
+                        'title': title,
+                        'content': content,
+                        'author': author,
+                        'length': length,
+                        'template': 'videos.html',
+                        'embedded': embedded,
+                        'thumbnail': thumbnail,
+                    }
+                )
 
     # return results
     return results
diff --git a/searx/engines/zlibrary.py b/searx/engines/zlibrary.py
index 180e9e355..81d93ac84 100644
--- a/searx/engines/zlibrary.py
+++ b/searx/engines/zlibrary.py
@@ -31,25 +31,23 @@ categories = ['files']
 paging = True
 base_url = ''
 
+
 def init(engine_settings=None):
-    global base_url # pylint: disable=global-statement
+    global base_url  # pylint: disable=global-statement
 
     if "base_url" not in engine_settings:
         resp = http_get('https://z-lib.org', timeout=5.0)
         if resp.ok:
             dom = html.fromstring(resp.text)
-            base_url = "https:" + extract_text(eval_xpath(dom,
-                './/a[contains(@class, "domain-check-link") and @data-mode="books"]/@href'
-            ))
+            base_url = "https:" + extract_text(
+                eval_xpath(dom, './/a[contains(@class, "domain-check-link") and @data-mode="books"]/@href')
+            )
     logger.debug("using base_url: %s" % base_url)
 
 
 def request(query, params):
     search_url = base_url + '/s/{search_query}/?page={pageno}'
-    params['url'] = search_url.format(
-        search_query=quote(query),
-        pageno=params['pageno']
-    )
+    params['url'] = search_url.format(search_query=quote(query), pageno=params['pageno'])
     return params
 
 
@@ -60,36 +58,34 @@ def response(resp):
     for item in dom.xpath('//div[@id="searchResultBox"]//div[contains(@class, "resItemBox")]'):
         result = {}
 
-        result["url"] = base_url + \
-            item.xpath('(.//a[starts-with(@href, "/book/")])[1]/@href')[0]
+        result["url"] = base_url + item.xpath('(.//a[starts-with(@href, "/book/")])[1]/@href')[0]
 
         result["title"] = extract_text(eval_xpath(item, './/*[@itemprop="name"]'))
 
-        year = extract_text(eval_xpath(
-            item, './/div[contains(@class, "property_year")]//div[contains(@class, "property_value")]'))
+        year = extract_text(
+            eval_xpath(item, './/div[contains(@class, "property_year")]//div[contains(@class, "property_value")]')
+        )
         if year:
             year = '(%s) ' % year
 
-        result["content"] = "{year}{authors}. {publisher}. Language: {language}. {file_type}. \
+        result[
+            "content"
+        ] = "{year}{authors}. {publisher}. Language: {language}. {file_type}. \
             Book rating: {book_rating}, book quality: {book_quality}".format(
-                year = year,
-                authors = extract_text(eval_xpath(item, './/div[@class="authors"]')),
-                publisher = extract_text(eval_xpath(item, './/div[@title="Publisher"]')),
-                file_type = extract_text(
-                    eval_xpath(
-                        item,
-                        './/div[contains(@class, "property__file")]//div[contains(@class, "property_value")]')),
-                language = extract_text(
-                    eval_xpath(
-                        item,
-                        './/div[contains(@class, "property_language")]//div[contains(@class, "property_value")]')),
-                book_rating = extract_text(
-                    eval_xpath(
-                        item, './/span[contains(@class, "book-rating-interest-score")]')),
-                book_quality = extract_text(
-                    eval_xpath(
-                        item, './/span[contains(@class, "book-rating-quality-score")]')),
-            )
+            year=year,
+            authors=extract_text(eval_xpath(item, './/div[@class="authors"]')),
+            publisher=extract_text(eval_xpath(item, './/div[@title="Publisher"]')),
+            file_type=extract_text(
+                eval_xpath(item, './/div[contains(@class, "property__file")]//div[contains(@class, "property_value")]')
+            ),
+            language=extract_text(
+                eval_xpath(
+                    item, './/div[contains(@class, "property_language")]//div[contains(@class, "property_value")]'
+                )
+            ),
+            book_rating=extract_text(eval_xpath(item, './/span[contains(@class, "book-rating-interest-score")]')),
+            book_quality=extract_text(eval_xpath(item, './/span[contains(@class, "book-rating-quality-score")]')),
+        )
 
         result["img_src"] = extract_text(eval_xpath(item, './/img[contains(@class, "cover")]/@data-src'))
 
diff --git a/searx/exceptions.py b/searx/exceptions.py
index 67a282da2..1b106d40c 100644
--- a/searx/exceptions.py
+++ b/searx/exceptions.py
@@ -21,7 +21,6 @@ class SearxException(Exception):
 
 
 class SearxParameterException(SearxException):
-
     def __init__(self, name, value):
         if value == '' or value is None:
             message = 'Empty ' + name + ' parameter'
diff --git a/searx/external_urls.py b/searx/external_urls.py
index 11c6a32d9..2657dba4b 100644
--- a/searx/external_urls.py
+++ b/searx/external_urls.py
@@ -8,7 +8,7 @@ IMDB_PREFIX_TO_URL_ID = {
     'mn': 'imdb_name',
     'ch': 'imdb_character',
     'co': 'imdb_company',
-    'ev': 'imdb_event'
+    'ev': 'imdb_event',
 }
 HTTP_WIKIMEDIA_IMAGE = 'http://commons.wikimedia.org/wiki/Special:FilePath/'
 
@@ -20,9 +20,9 @@ def get_imdb_url_id(imdb_item_id):
 
 def get_wikimedia_image_id(url):
     if url.startswith(HTTP_WIKIMEDIA_IMAGE):
-        return url[len(HTTP_WIKIMEDIA_IMAGE):]
+        return url[len(HTTP_WIKIMEDIA_IMAGE) :]
     if url.startswith('File:'):
-        return url[len('File:'):]
+        return url[len('File:') :]
     return url
 
 
@@ -52,10 +52,12 @@ def get_external_url(url_id, item_id, alternative="default"):
 
 
 def get_earth_coordinates_url(latitude, longitude, osm_zoom, alternative='default'):
-    url = get_external_url('map', None, alternative)\
-        .replace('${latitude}', str(latitude))\
-        .replace('${longitude}', str(longitude))\
+    url = (
+        get_external_url('map', None, alternative)
+        .replace('${latitude}', str(latitude))
+        .replace('${longitude}', str(longitude))
         .replace('${zoom}', str(osm_zoom))
+    )
     return url
 
 
diff --git a/searx/flaskfix.py b/searx/flaskfix.py
index 47aabfa53..326c4b981 100644
--- a/searx/flaskfix.py
+++ b/searx/flaskfix.py
@@ -29,6 +29,7 @@ class ReverseProxyPathFix:
 
     :param wsgi_app: the WSGI application
     '''
+
     # pylint: disable=too-few-public-methods
 
     def __init__(self, wsgi_app):
@@ -58,7 +59,7 @@ class ReverseProxyPathFix:
             environ['SCRIPT_NAME'] = script_name
             path_info = environ['PATH_INFO']
             if path_info.startswith(script_name):
-                environ['PATH_INFO'] = path_info[len(script_name):]
+                environ['PATH_INFO'] = path_info[len(script_name) :]
 
         scheme = self.scheme or environ.get('HTTP_X_SCHEME', '')
         if scheme:
diff --git a/searx/languages.py b/searx/languages.py
index c44eb0b9e..1f157e517 100644
--- a/searx/languages.py
+++ b/searx/languages.py
@@ -1,8 +1,8 @@
 # -*- coding: utf-8 -*-
 # list of language codes
 # this file is generated automatically by utils/fetch_languages.py
-language_codes = \
-(   ('af-ZA', 'Afrikaans', '', 'Afrikaans'),
+language_codes = (
+    ('af-ZA', 'Afrikaans', '', 'Afrikaans'),
     ('ar-EG', 'العربية', '', 'Arabic'),
     ('be-BY', 'Беларуская', '', 'Belarusian'),
     ('bg-BG', 'Български', '', 'Bulgarian'),
@@ -74,4 +74,5 @@ language_codes = \
     ('zh', '中文', '', 'Chinese'),
     ('zh-CN', '中文', '中国', 'Chinese'),
     ('zh-HK', '中文', '中國香港特別行政區', 'Chinese'),
-    ('zh-TW', '中文', '台灣', 'Chinese'))
\ No newline at end of file
+    ('zh-TW', '中文', '台灣', 'Chinese'),
+)
diff --git a/searx/locales.py b/searx/locales.py
index b791f35f3..62f64204f 100644
--- a/searx/locales.py
+++ b/searx/locales.py
@@ -51,11 +51,10 @@ def _get_locale_name(locale, locale_name):
 
 
 def initialize_locales(directory):
-    """Initialize global names :py:obj:`LOCALE_NAMES`, :py:obj:`RTL_LOCALES`.
-    """
+    """Initialize global names :py:obj:`LOCALE_NAMES`, :py:obj:`RTL_LOCALES`."""
     for dirname in sorted(os.listdir(directory)):
         # Based on https://flask-babel.tkte.ch/_modules/flask_babel.html#Babel.list_translations
-        if not os.path.isdir( os.path.join(directory, dirname, 'LC_MESSAGES') ):
+        if not os.path.isdir(os.path.join(directory, dirname, 'LC_MESSAGES')):
             continue
         locale_name = dirname.replace('_', '-')
         info = LOCALE_NAMES.get(locale_name)
diff --git a/searx/metrics/__init__.py b/searx/metrics/__init__.py
index 995f182af..37f0ba121 100644
--- a/searx/metrics/__init__.py
+++ b/searx/metrics/__init__.py
@@ -12,11 +12,19 @@ from searx.engines import engines
 from .models import HistogramStorage, CounterStorage
 from .error_recorder import count_error, count_exception, errors_per_engines
 
-__all__ = ["initialize",
-           "get_engines_stats", "get_engine_errors",
-           "histogram", "histogram_observe", "histogram_observe_time",
-           "counter", "counter_inc", "counter_add",
-           "count_error", "count_exception"]
+__all__ = [
+    "initialize",
+    "get_engines_stats",
+    "get_engine_errors",
+    "histogram",
+    "histogram_observe",
+    "histogram_observe_time",
+    "counter",
+    "counter_inc",
+    "counter_add",
+    "count_error",
+    "count_exception",
+]
 
 
 ENDPOINTS = {'search'}
@@ -72,7 +80,7 @@ def initialize(engine_names=None):
 
     # max_timeout = max of all the engine.timeout
     max_timeout = 2
-    for engine_name in (engine_names or engines):
+    for engine_name in engine_names or engines:
         if engine_name in engines:
             max_timeout = max(max_timeout, engines[engine_name].timeout)
 
@@ -81,7 +89,7 @@ def initialize(engine_names=None):
     histogram_size = int(1.5 * max_timeout / histogram_width)
 
     # engines
-    for engine_name in (engine_names or engines):
+    for engine_name in engine_names or engines:
         # search count
         counter_storage.configure('engine', engine_name, 'search', 'count', 'sent')
         counter_storage.configure('engine', engine_name, 'search', 'count', 'successful')
@@ -112,17 +120,19 @@ def get_engine_errors(engline_name_list):
         r = []
         for context, count in sorted_context_count_list:
             percentage = round(20 * count / sent_search_count) * 5
-            r.append({
-                'filename': context.filename,
-                'function': context.function,
-                'line_no': context.line_no,
-                'code': context.code,
-                'exception_classname': context.exception_classname,
-                'log_message': context.log_message,
-                'log_parameters': context.log_parameters,
-                'secondary': context.secondary,
-                'percentage': percentage,
-            })
+            r.append(
+                {
+                    'filename': context.filename,
+                    'function': context.function,
+                    'line_no': context.line_no,
+                    'code': context.code,
+                    'exception_classname': context.exception_classname,
+                    'log_message': context.log_message,
+                    'log_parameters': context.log_parameters,
+                    'secondary': context.secondary,
+                    'percentage': percentage,
+                }
+            )
         result[engine_name] = sorted(r, reverse=True, key=lambda d: d['percentage'])
     return result
 
diff --git a/searx/metrics/error_recorder.py b/searx/metrics/error_recorder.py
index 37594e5e8..76d27f64f 100644
--- a/searx/metrics/error_recorder.py
+++ b/searx/metrics/error_recorder.py
@@ -3,8 +3,12 @@ import inspect
 from json import JSONDecodeError
 from urllib.parse import urlparse
 from httpx import HTTPError, HTTPStatusError
-from searx.exceptions import (SearxXPathSyntaxException, SearxEngineXPathException, SearxEngineAPIException,
-                              SearxEngineAccessDeniedException)
+from searx.exceptions import (
+    SearxXPathSyntaxException,
+    SearxEngineXPathException,
+    SearxEngineAPIException,
+    SearxEngineAccessDeniedException,
+)
 from searx import searx_parent_dir
 from searx.engines import engines
 
@@ -14,8 +18,16 @@ errors_per_engines = {}
 
 class ErrorContext:
 
-    __slots__ = ('filename', 'function', 'line_no', 'code', 'exception_classname',
-                 'log_message', 'log_parameters', 'secondary')
+    __slots__ = (
+        'filename',
+        'function',
+        'line_no',
+        'code',
+        'exception_classname',
+        'log_message',
+        'log_parameters',
+        'secondary',
+    )
 
     def __init__(self, filename, function, line_no, code, exception_classname, log_message, log_parameters, secondary):
         self.filename = filename
@@ -30,19 +42,41 @@ class ErrorContext:
     def __eq__(self, o) -> bool:
         if not isinstance(o, ErrorContext):
             return False
-        return self.filename == o.filename and self.function == o.function and self.line_no == o.line_no\
-            and self.code == o.code and self.exception_classname == o.exception_classname\
-            and self.log_message == o.log_message and self.log_parameters == o.log_parameters \
+        return (
+            self.filename == o.filename
+            and self.function == o.function
+            and self.line_no == o.line_no
+            and self.code == o.code
+            and self.exception_classname == o.exception_classname
+            and self.log_message == o.log_message
+            and self.log_parameters == o.log_parameters
             and self.secondary == o.secondary
+        )
 
     def __hash__(self):
-        return hash((self.filename, self.function, self.line_no, self.code, self.exception_classname, self.log_message,
-                     self.log_parameters, self.secondary))
+        return hash(
+            (
+                self.filename,
+                self.function,
+                self.line_no,
+                self.code,
+                self.exception_classname,
+                self.log_message,
+                self.log_parameters,
+                self.secondary,
+            )
+        )
 
     def __repr__(self):
-        return "ErrorContext({!r}, {!r}, {!r}, {!r}, {!r}, {!r}) {!r}".\
-            format(self.filename, self.line_no, self.code, self.exception_classname, self.log_message,
-                   self.log_parameters, self.secondary)
+        return "ErrorContext({!r}, {!r}, {!r}, {!r}, {!r}, {!r}) {!r}".format(
+            self.filename,
+            self.line_no,
+            self.code,
+            self.exception_classname,
+            self.log_message,
+            self.log_parameters,
+            self.secondary,
+        )
 
 
 def add_error_context(engine_name: str, error_context: ErrorContext) -> None:
@@ -68,8 +102,9 @@ def get_hostname(exc: HTTPError) -> typing.Optional[None]:
     return urlparse(url).netloc
 
 
-def get_request_exception_messages(exc: HTTPError)\
-        -> typing.Tuple[typing.Optional[str], typing.Optional[str], typing.Optional[str]]:
+def get_request_exception_messages(
+    exc: HTTPError,
+) -> typing.Tuple[typing.Optional[str], typing.Optional[str], typing.Optional[str]]:
     url = None
     status_code = None
     reason = None
@@ -90,11 +125,11 @@ def get_request_exception_messages(exc: HTTPError)\
 
 def get_messages(exc, filename) -> typing.Tuple:
     if isinstance(exc, JSONDecodeError):
-        return (exc.msg, )
+        return (exc.msg,)
     if isinstance(exc, TypeError):
-        return (str(exc), )
+        return (str(exc),)
     if isinstance(exc, ValueError) and 'lxml' in filename:
-        return (str(exc), )
+        return (str(exc),)
     if isinstance(exc, HTTPError):
         return get_request_exception_messages(exc)
     if isinstance(exc, SearxXPathSyntaxException):
@@ -102,9 +137,9 @@ def get_messages(exc, filename) -> typing.Tuple:
     if isinstance(exc, SearxEngineXPathException):
         return (exc.xpath_str, exc.message)
     if isinstance(exc, SearxEngineAPIException):
-        return (str(exc.args[0]), )
+        return (str(exc.args[0]),)
     if isinstance(exc, SearxEngineAccessDeniedException):
-        return (exc.message, )
+        return (exc.message,)
     return ()
 
 
@@ -121,7 +156,7 @@ def get_error_context(framerecords, exception_classname, log_message, log_parame
     searx_frame = get_trace(framerecords)
     filename = searx_frame.filename
     if filename.startswith(searx_parent_dir):
-        filename = filename[len(searx_parent_dir) + 1:]
+        filename = filename[len(searx_parent_dir) + 1 :]
     function = searx_frame.function
     line_no = searx_frame.lineno
     code = searx_frame.code_context[0].strip()
@@ -140,8 +175,9 @@ def count_exception(engine_name: str, exc: Exception, secondary: bool = False) -
         del framerecords
 
 
-def count_error(engine_name: str, log_message: str, log_parameters: typing.Optional[typing.Tuple] = None,
-                secondary: bool = False) -> None:
+def count_error(
+    engine_name: str, log_message: str, log_parameters: typing.Optional[typing.Tuple] = None, secondary: bool = False
+) -> None:
     framerecords = list(reversed(inspect.stack()[1:]))
     try:
         error_context = get_error_context(framerecords, None, log_message, log_parameters or (), secondary)
diff --git a/searx/metrics/models.py b/searx/metrics/models.py
index 8936a51e3..d42569b7f 100644
--- a/searx/metrics/models.py
+++ b/searx/metrics/models.py
@@ -58,7 +58,7 @@ class Histogram:
 
     @property
     def quartile_percentage(self):
-        ''' Quartile in percentage '''
+        '''Quartile in percentage'''
         with self._lock:
             if self._count > 0:
                 return [int(q * 100 / self._count) for q in self._quartiles]
diff --git a/searx/network/__init__.py b/searx/network/__init__.py
index 82959e355..7d02a0014 100644
--- a/searx/network/__init__.py
+++ b/searx/network/__init__.py
@@ -35,7 +35,7 @@ except ImportError:
             self._count.release()
 
         def get(self):
-            if not self._count.acquire(True):  #pylint: disable=consider-using-with
+            if not self._count.acquire(True):  # pylint: disable=consider-using-with
                 raise Empty
             return self._queue.popleft()
 
@@ -43,6 +43,7 @@ except ImportError:
 THREADLOCAL = threading.local()
 """Thread-local data is data for thread specific values."""
 
+
 def reset_time_for_thread():
     THREADLOCAL.total_time = 0
 
@@ -187,10 +188,7 @@ async def stream_chunk_to_queue(network, queue, method, url, **kwargs):
 def _stream_generator(method, url, **kwargs):
     queue = SimpleQueue()
     network = get_context_network()
-    future = asyncio.run_coroutine_threadsafe(
-        stream_chunk_to_queue(network, queue, method, url, **kwargs),
-        get_loop()
-    )
+    future = asyncio.run_coroutine_threadsafe(stream_chunk_to_queue(network, queue, method, url, **kwargs), get_loop())
 
     # yield chunks
     obj_or_exception = queue.get()
@@ -203,10 +201,7 @@ def _stream_generator(method, url, **kwargs):
 
 
 def _close_response_method(self):
-    asyncio.run_coroutine_threadsafe(
-        self.aclose(),
-        get_loop()
-    )
+    asyncio.run_coroutine_threadsafe(self.aclose(), get_loop())
     # reach the end of _self.generator ( _stream_generator ) to an avoid memory leak.
     # it makes sure that :
     # * the httpx response is closed (see the stream_chunk_to_queue function)
diff --git a/searx/network/client.py b/searx/network/client.py
index a6cec352d..cd1e41460 100644
--- a/searx/network/client.py
+++ b/searx/network/client.py
@@ -10,12 +10,7 @@ import anyio
 import httpcore
 import httpx
 from httpx_socks import AsyncProxyTransport
-from python_socks import (
-    parse_proxy_url,
-    ProxyConnectionError,
-    ProxyTimeoutError,
-    ProxyError
-)
+from python_socks import parse_proxy_url, ProxyConnectionError, ProxyTimeoutError, ProxyError
 
 from searx import logger
 
@@ -41,9 +36,7 @@ TRANSPORT_KWARGS = {
 
 
 # pylint: disable=protected-access
-async def close_connections_for_url(
-    connection_pool: httpcore.AsyncConnectionPool, url: httpcore._utils.URL
-):
+async def close_connections_for_url(connection_pool: httpcore.AsyncConnectionPool, url: httpcore._utils.URL):
 
     origin = httpcore._utils.url_to_origin(url)
     logger.debug('Drop connections for %r', origin)
@@ -54,6 +47,8 @@ async def close_connections_for_url(
             await connection.aclose()
         except httpx.NetworkError as e:
             logger.warning('Error closing an existing connection', exc_info=e)
+
+
 # pylint: enable=protected-access
 
 
@@ -67,9 +62,7 @@ def get_sslcontexts(proxy_url=None, cert=None, verify=True, trust_env=True, http
 class AsyncHTTPTransportNoHttp(httpx.AsyncHTTPTransport):
     """Block HTTP request"""
 
-    async def handle_async_request(
-        self, method, url, headers=None, stream=None, extensions=None
-    ):
+    async def handle_async_request(self, method, url, headers=None, stream=None, extensions=None):
         raise httpx.UnsupportedProtocol('HTTP protocol is disabled')
 
 
@@ -83,9 +76,7 @@ class AsyncProxyTransportFixed(AsyncProxyTransport):
     Note: AsyncProxyTransport inherit from AsyncConnectionPool
     """
 
-    async def handle_async_request(
-        self, method, url, headers=None, stream=None, extensions=None
-    ):
+    async def handle_async_request(self, method, url, headers=None, stream=None, extensions=None):
         retry = 2
         while retry > 0:
             retry -= 1
@@ -116,9 +107,7 @@ class AsyncProxyTransportFixed(AsyncProxyTransport):
 class AsyncHTTPTransportFixed(httpx.AsyncHTTPTransport):
     """Fix httpx.AsyncHTTPTransport"""
 
-    async def handle_async_request(
-        self, method, url, headers=None, stream=None, extensions=None
-    ):
+    async def handle_async_request(self, method, url, headers=None, stream=None, extensions=None):
         retry = 2
         while retry > 0:
             retry -= 1
@@ -152,14 +141,17 @@ def get_transport_for_socks_proxy(verify, http2, local_address, proxy_url, limit
     rdns = False
     socks5h = 'socks5h://'
     if proxy_url.startswith(socks5h):
-        proxy_url = 'socks5://' + proxy_url[len(socks5h):]
+        proxy_url = 'socks5://' + proxy_url[len(socks5h) :]
         rdns = True
 
     proxy_type, proxy_host, proxy_port, proxy_username, proxy_password = parse_proxy_url(proxy_url)
     verify = get_sslcontexts(proxy_url, None, True, False, http2) if verify is True else verify
     return AsyncProxyTransportFixed(
-        proxy_type=proxy_type, proxy_host=proxy_host, proxy_port=proxy_port,
-        username=proxy_username, password=proxy_password,
+        proxy_type=proxy_type,
+        proxy_host=proxy_host,
+        proxy_port=proxy_port,
+        username=proxy_username,
+        password=proxy_password,
         rdns=rdns,
         loop=get_loop(),
         verify=verify,
@@ -169,7 +161,7 @@ def get_transport_for_socks_proxy(verify, http2, local_address, proxy_url, limit
         max_keepalive_connections=limit.max_keepalive_connections,
         keepalive_expiry=limit.keepalive_expiry,
         retries=retries,
-        **TRANSPORT_KWARGS
+        **TRANSPORT_KWARGS,
     )
 
 
@@ -183,36 +175,40 @@ def get_transport(verify, http2, local_address, proxy_url, limit, retries):
         proxy=httpx._config.Proxy(proxy_url) if proxy_url else None,
         limits=limit,
         retries=retries,
-        **TRANSPORT_KWARGS
+        **TRANSPORT_KWARGS,
     )
 
 
 def new_client(
-        # pylint: disable=too-many-arguments
-        enable_http, verify, enable_http2,
-        max_connections, max_keepalive_connections, keepalive_expiry,
-        proxies, local_address, retries, max_redirects, hook_log_response  ):
+    # pylint: disable=too-many-arguments
+    enable_http,
+    verify,
+    enable_http2,
+    max_connections,
+    max_keepalive_connections,
+    keepalive_expiry,
+    proxies,
+    local_address,
+    retries,
+    max_redirects,
+    hook_log_response,
+):
     limit = httpx.Limits(
         max_connections=max_connections,
         max_keepalive_connections=max_keepalive_connections,
-        keepalive_expiry=keepalive_expiry
+        keepalive_expiry=keepalive_expiry,
     )
     # See https://www.python-httpx.org/advanced/#routing
     mounts = {}
     for pattern, proxy_url in proxies.items():
         if not enable_http and pattern.startswith('http://'):
             continue
-        if (proxy_url.startswith('socks4://')
-           or proxy_url.startswith('socks5://')
-            or proxy_url.startswith('socks5h://')
-        ):
+        if proxy_url.startswith('socks4://') or proxy_url.startswith('socks5://') or proxy_url.startswith('socks5h://'):
             mounts[pattern] = get_transport_for_socks_proxy(
                 verify, enable_http2, local_address, proxy_url, limit, retries
             )
         else:
-            mounts[pattern] = get_transport(
-                verify, enable_http2, local_address, proxy_url, limit, retries
-            )
+            mounts[pattern] = get_transport(verify, enable_http2, local_address, proxy_url, limit, retries)
 
     if not enable_http:
         mounts['http://'] = AsyncHTTPTransportNoHttp()
@@ -221,7 +217,7 @@ def new_client(
 
     event_hooks = None
     if hook_log_response:
-        event_hooks = {'response': [ hook_log_response ]}
+        event_hooks = {'response': [hook_log_response]}
 
     return httpx.AsyncClient(
         transport=transport,
diff --git a/searx/network/network.py b/searx/network/network.py
index 613b9ff27..9e14e14bd 100644
--- a/searx/network/network.py
+++ b/searx/network/network.py
@@ -31,39 +31,49 @@ PROXY_PATTERN_MAPPING = {
     'socks5h:': 'socks5h://',
 }
 
-ADDRESS_MAPPING = {
-    'ipv4': '0.0.0.0',
-    'ipv6': '::'
-}
+ADDRESS_MAPPING = {'ipv4': '0.0.0.0', 'ipv6': '::'}
 
 
 class Network:
 
     __slots__ = (
-        'enable_http', 'verify', 'enable_http2',
-        'max_connections', 'max_keepalive_connections', 'keepalive_expiry',
-        'local_addresses', 'proxies', 'using_tor_proxy', 'max_redirects', 'retries', 'retry_on_http_error',
-        '_local_addresses_cycle', '_proxies_cycle', '_clients', '_logger'
+        'enable_http',
+        'verify',
+        'enable_http2',
+        'max_connections',
+        'max_keepalive_connections',
+        'keepalive_expiry',
+        'local_addresses',
+        'proxies',
+        'using_tor_proxy',
+        'max_redirects',
+        'retries',
+        'retry_on_http_error',
+        '_local_addresses_cycle',
+        '_proxies_cycle',
+        '_clients',
+        '_logger',
     )
 
     _TOR_CHECK_RESULT = {}
 
     def __init__(
-            # pylint: disable=too-many-arguments
-            self,
-            enable_http=True,
-            verify=True,
-            enable_http2=False,
-            max_connections=None,
-            max_keepalive_connections=None,
-            keepalive_expiry=None,
-            proxies=None,
-            using_tor_proxy=False,
-            local_addresses=None,
-            retries=0,
-            retry_on_http_error=None,
-            max_redirects=30,
-            logger_name=None):
+        # pylint: disable=too-many-arguments
+        self,
+        enable_http=True,
+        verify=True,
+        enable_http2=False,
+        max_connections=None,
+        max_keepalive_connections=None,
+        keepalive_expiry=None,
+        proxies=None,
+        using_tor_proxy=False,
+        local_addresses=None,
+        retries=0,
+        retry_on_http_error=None,
+        max_redirects=30,
+        logger_name=None,
+    ):
 
         self.enable_http = enable_http
         self.verify = verify
@@ -144,9 +154,7 @@ class Network:
         response_line = f"{response.http_version} {status}"
         content_type = response.headers.get("Content-Type")
         content_type = f' ({content_type})' if content_type else ''
-        self._logger.debug(
-            f'HTTP Request: {request.method} {request.url} "{response_line}"{content_type}'
-        )
+        self._logger.debug(f'HTTP Request: {request.method} {request.url} "{response_line}"{content_type}')
 
     @staticmethod
     async def check_tor_proxy(client: httpx.AsyncClient, proxies) -> bool:
@@ -187,7 +195,7 @@ class Network:
                 local_address,
                 0,
                 max_redirects,
-                hook_log_response
+                hook_log_response,
             )
             if self.using_tor_proxy and not await self.check_tor_proxy(client, proxies):
                 await client.aclose()
@@ -201,6 +209,7 @@ class Network:
                 await client.aclose()
             except httpx.HTTPError:
                 pass
+
         await asyncio.gather(*[close_client(client) for client in self._clients.values()], return_exceptions=False)
 
     @staticmethod
@@ -214,7 +223,8 @@ class Network:
 
     def is_valid_respones(self, response):
         # pylint: disable=too-many-boolean-expressions
-        if ((self.retry_on_http_error is True and 400 <= response.status_code <= 599)
+        if (
+            (self.retry_on_http_error is True and 400 <= response.status_code <= 599)
             or (isinstance(self.retry_on_http_error, list) and response.status_code in self.retry_on_http_error)
             or (isinstance(self.retry_on_http_error, int) and response.status_code == self.retry_on_http_error)
         ):
@@ -269,6 +279,7 @@ def check_network_configuration():
                     network._logger.exception('Error')  # pylint: disable=protected-access
                     exception_count += 1
         return exception_count
+
     future = asyncio.run_coroutine_threadsafe(check(), get_loop())
     exception_count = future.result()
     if exception_count > 0:
@@ -279,6 +290,7 @@ def initialize(settings_engines=None, settings_outgoing=None):
     # pylint: disable=import-outside-toplevel)
     from searx.engines import engines
     from searx import settings
+
     # pylint: enable=import-outside-toplevel)
 
     settings_engines = settings_engines or settings['engines']
diff --git a/searx/network/raise_for_httperror.py b/searx/network/raise_for_httperror.py
index a2f554614..414074977 100644
--- a/searx/network/raise_for_httperror.py
+++ b/searx/network/raise_for_httperror.py
@@ -10,13 +10,14 @@ from searx.exceptions import (
     SearxEngineAccessDeniedException,
 )
 
+
 def is_cloudflare_challenge(resp):
     if resp.status_code in [429, 503]:
-        if (('__cf_chl_jschl_tk__=' in resp.text)
-            or ('/cdn-cgi/challenge-platform/' in resp.text
-                and 'orchestrate/jsch/v1' in resp.text
-                and 'window._cf_chl_enter(' in resp.text
-            )):
+        if ('__cf_chl_jschl_tk__=' in resp.text) or (
+            '/cdn-cgi/challenge-platform/' in resp.text
+            and 'orchestrate/jsch/v1' in resp.text
+            and 'window._cf_chl_enter(' in resp.text
+        ):
             return True
     if resp.status_code == 403 and '__cf_chl_captcha_tk__=' in resp.text:
         return True
@@ -32,21 +33,14 @@ def raise_for_cloudflare_captcha(resp):
         if is_cloudflare_challenge(resp):
             # https://support.cloudflare.com/hc/en-us/articles/200170136-Understanding-Cloudflare-Challenge-Passage-Captcha-
             # suspend for 2 weeks
-            raise SearxEngineCaptchaException(
-                message='Cloudflare CAPTCHA',
-                suspended_time=3600 * 24 * 15
-            )
+            raise SearxEngineCaptchaException(message='Cloudflare CAPTCHA', suspended_time=3600 * 24 * 15)
 
         if is_cloudflare_firewall(resp):
-            raise SearxEngineAccessDeniedException(
-                message='Cloudflare Firewall', suspended_time=3600 * 24
-            )
+            raise SearxEngineAccessDeniedException(message='Cloudflare Firewall', suspended_time=3600 * 24)
 
 
 def raise_for_recaptcha(resp):
-    if (resp.status_code == 503
-        and '"https://www.google.com/recaptcha/' in resp.text
-    ):
+    if resp.status_code == 503 and '"https://www.google.com/recaptcha/' in resp.text:
         raise SearxEngineCaptchaException(message='ReCAPTCHA', suspended_time=3600 * 24 * 7)
 
 
@@ -71,8 +65,7 @@ def raise_for_httperror(resp):
         raise_for_captcha(resp)
         if resp.status_code in (402, 403):
             raise SearxEngineAccessDeniedException(
-                message='HTTP error ' + str(resp.status_code),
-                suspended_time=3600 * 24
+                message='HTTP error ' + str(resp.status_code), suspended_time=3600 * 24
             )
         if resp.status_code == 429:
             raise SearxEngineTooManyRequestsException()
diff --git a/searx/plugins/__init__.py b/searx/plugins/__init__.py
index 4c824da28..7815c2099 100644
--- a/searx/plugins/__init__.py
+++ b/searx/plugins/__init__.py
@@ -51,11 +51,7 @@ def sync_resource(base_path, resource_path, name, target_dir, plugin_dir):
             dep_stat = stat(dep_path)
             utime(resource_path, ns=(dep_stat.st_atime_ns, dep_stat.st_mtime_ns))
         except IOError:
-            logger.critical(
-                "failed to copy plugin resource {0} for plugin {1}".format(
-                    file_name, name
-                )
-            )
+            logger.critical("failed to copy plugin resource {0} for plugin {1}".format(file_name, name))
             sys.exit(3)
 
     # returning with the web path of the resource
@@ -66,36 +62,28 @@ def prepare_package_resources(plugin, plugin_module_name):
     plugin_base_path = dirname(abspath(plugin.__file__))
 
     plugin_dir = plugin_module_name
-    target_dir = join(
-        settings["ui"]["static_path"], "plugins/external_plugins", plugin_dir
-    )
+    target_dir = join(settings["ui"]["static_path"], "plugins/external_plugins", plugin_dir)
     try:
         makedirs(target_dir, exist_ok=True)
     except IOError:
-        logger.critical(
-            "failed to create resource directory {0} for plugin {1}".format(
-                target_dir, plugin_module_name
-            )
-        )
+        logger.critical("failed to create resource directory {0} for plugin {1}".format(target_dir, plugin_module_name))
         sys.exit(3)
 
     resources = []
 
     if hasattr(plugin, "js_dependencies"):
         resources.extend(map(basename, plugin.js_dependencies))
-        plugin.js_dependencies = ([
-            sync_resource(
-                plugin_base_path, x, plugin_module_name, target_dir, plugin_dir
-            ) for x in plugin.js_dependencies
-            ])
+        plugin.js_dependencies = [
+            sync_resource(plugin_base_path, x, plugin_module_name, target_dir, plugin_dir)
+            for x in plugin.js_dependencies
+        ]
 
     if hasattr(plugin, "css_dependencies"):
         resources.extend(map(basename, plugin.css_dependencies))
-        plugin.css_dependencies = ([
-            sync_resource(
-                plugin_base_path, x, plugin_module_name, target_dir, plugin_dir
-            ) for x in plugin.css_dependencies
-            ])
+        plugin.css_dependencies = [
+            sync_resource(plugin_base_path, x, plugin_module_name, target_dir, plugin_dir)
+            for x in plugin.css_dependencies
+        ]
 
     for f in listdir(target_dir):
         if basename(f) not in resources:
@@ -104,9 +92,7 @@ def prepare_package_resources(plugin, plugin_module_name):
                 remove(resource_path)
             except IOError:
                 logger.critical(
-                    "failed to remove unused resource file {0} for plugin {1}".format(
-                        resource_path, plugin_module_name
-                    )
+                    "failed to remove unused resource file {0} for plugin {1}".format(resource_path, plugin_module_name)
                 )
                 sys.exit(3)
 
@@ -137,9 +123,7 @@ def load_plugin(plugin_module_name, external):
 
     for plugin_attr, plugin_attr_type in required_attrs:
         if not hasattr(plugin, plugin_attr):
-            logger.critical(
-                '%s: missing attribute "%s", cannot load plugin', plugin, plugin_attr
-            )
+            logger.critical('%s: missing attribute "%s", cannot load plugin', plugin, plugin_attr)
             sys.exit(3)
         attr = getattr(plugin, plugin_attr)
         if not isinstance(attr, plugin_attr_type):
@@ -152,9 +136,7 @@ def load_plugin(plugin_module_name, external):
             sys.exit(3)
 
     for plugin_attr, plugin_attr_type in optional_attrs:
-        if not hasattr(plugin, plugin_attr) or not isinstance(
-            getattr(plugin, plugin_attr), plugin_attr_type
-        ):
+        if not hasattr(plugin, plugin_attr) or not isinstance(getattr(plugin, plugin_attr), plugin_attr_type):
             setattr(plugin, plugin_attr, plugin_attr_type())
 
     if not hasattr(plugin, "preference_section"):
@@ -164,19 +146,12 @@ def load_plugin(plugin_module_name, external):
     if plugin.preference_section == "query":
         for plugin_attr in ("query_keywords", "query_examples"):
             if not hasattr(plugin, plugin_attr):
-                logger.critical(
-                    'missing attribute "{0}", cannot load plugin: {1}'.format(
-                        plugin_attr, plugin
-                    )
-                )
+                logger.critical('missing attribute "{0}", cannot load plugin: {1}'.format(plugin_attr, plugin))
                 sys.exit(3)
 
     if settings.get("enabled_plugins"):
         # searx compatibility: plugin.name in settings['enabled_plugins']
-        plugin.default_on = (
-            plugin.name in settings["enabled_plugins"]
-            or plugin.id in settings["enabled_plugins"]
-        )
+        plugin.default_on = plugin.name in settings["enabled_plugins"] or plugin.id in settings["enabled_plugins"]
 
     # copy ressources if this is an external plugin
     if external:
@@ -193,9 +168,7 @@ def load_and_initialize_plugin(plugin_module_name, external, init_args):
         try:
             return plugin if plugin.init(*init_args) else None
         except Exception:  # pylint: disable=broad-except
-            plugin.logger.exception(
-                "Exception while calling init, the plugin is disabled"
-            )
+            plugin.logger.exception("Exception while calling init, the plugin is disabled")
             return None
     return plugin
 
diff --git a/searx/plugins/oa_doi_rewrite.py b/searx/plugins/oa_doi_rewrite.py
index 2dcc01e05..54d28bc9a 100644
--- a/searx/plugins/oa_doi_rewrite.py
+++ b/searx/plugins/oa_doi_rewrite.py
@@ -39,7 +39,7 @@ def on_result(request, search, result):
     if doi and len(doi) < 50:
         for suffix in ('/', '.pdf', '.xml', '/full', '/meta', '/abstract'):
             if doi.endswith(suffix):
-                doi = doi[:-len(suffix)]
+                doi = doi[: -len(suffix)]
         result['url'] = get_doi_resolver(request.preferences) + doi
         result['parsed_url'] = urlparse(result['url'])
     return True
diff --git a/searx/plugins/search_on_category_select.py b/searx/plugins/search_on_category_select.py
index 2a38cac78..48d537cee 100644
--- a/searx/plugins/search_on_category_select.py
+++ b/searx/plugins/search_on_category_select.py
@@ -15,9 +15,11 @@ along with searx. If not, see < http://www.gnu.org/licenses/ >.
 (C) 2015 by Adam Tauber, <asciimoo@gmail.com>
 '''
 from flask_babel import gettext
+
 name = gettext('Search on category select')
-description = gettext('Perform search immediately if a category selected. '
-                      'Disable to select multiple categories. (JavaScript required)')
+description = gettext(
+    'Perform search immediately if a category selected. ' 'Disable to select multiple categories. (JavaScript required)'
+)
 default_on = True
 preference_section = 'ui'
 
diff --git a/searx/plugins/self_info.py b/searx/plugins/self_info.py
index 053899483..29bd5ca5c 100644
--- a/searx/plugins/self_info.py
+++ b/searx/plugins/self_info.py
@@ -16,6 +16,7 @@ along with searx. If not, see < http://www.gnu.org/licenses/ >.
 '''
 from flask_babel import gettext
 import re
+
 name = gettext('Self Informations')
 description = gettext('Displays your IP if the query is "ip" and your user agent if the query contains "user agent".')
 default_on = True
diff --git a/searx/plugins/tracker_url_remover.py b/searx/plugins/tracker_url_remover.py
index 98ddddbcd..42c58e524 100644
--- a/searx/plugins/tracker_url_remover.py
+++ b/searx/plugins/tracker_url_remover.py
@@ -19,10 +19,12 @@ from flask_babel import gettext
 import re
 from urllib.parse import urlunparse, parse_qsl, urlencode
 
-regexes = {re.compile(r'utm_[^&]+'),
-           re.compile(r'(wkey|wemail)[^&]*'),
-           re.compile(r'(_hsenc|_hsmi|hsCtaTracking|__hssc|__hstc|__hsfp)[^&]*'),
-           re.compile(r'&$')}
+regexes = {
+    re.compile(r'utm_[^&]+'),
+    re.compile(r'(wkey|wemail)[^&]*'),
+    re.compile(r'(_hsenc|_hsmi|hsCtaTracking|__hssc|__hstc|__hsfp)[^&]*'),
+    re.compile(r'&$'),
+}
 
 name = gettext('Tracker URL remover')
 description = gettext('Remove trackers arguments from the returned URL')
diff --git a/searx/plugins/vim_hotkeys.py b/searx/plugins/vim_hotkeys.py
index 47b830c79..fb61d413b 100644
--- a/searx/plugins/vim_hotkeys.py
+++ b/searx/plugins/vim_hotkeys.py
@@ -1,9 +1,11 @@
 from flask_babel import gettext
 
 name = gettext('Vim-like hotkeys')
-description = gettext('Navigate search results with Vim-like hotkeys '
-                      '(JavaScript required). '
-                      'Press "h" key on main or result page to get help.')
+description = gettext(
+    'Navigate search results with Vim-like hotkeys '
+    '(JavaScript required). '
+    'Press "h" key on main or result page to get help.'
+)
 default_on = False
 preference_section = 'ui'
 
diff --git a/searx/preferences.py b/searx/preferences.py
index 49f6ef202..2a9b0af0c 100644
--- a/searx/preferences.py
+++ b/searx/preferences.py
@@ -21,14 +21,12 @@ DOI_RESOLVERS = list(settings['doi_resolvers'])
 
 
 class MissingArgumentException(Exception):
-    """Exption from ``cls._post_init`` when a argument is missed.
-    """
+    """Exption from ``cls._post_init`` when a argument is missed."""
 
 
 class ValidationException(Exception):
 
-    """Exption from ``cls._post_init`` when configuration value is invalid.
-    """
+    """Exption from ``cls._post_init`` when configuration value is invalid."""
 
 
 class Setting:
@@ -84,8 +82,7 @@ class EnumStringSetting(Setting):
             raise ValidationException('Invalid value: "{0}"'.format(selection))
 
     def parse(self, data):
-        """Parse and validate ``data`` and store the result at ``self.value``
-        """
+        """Parse and validate ``data`` and store the result at ``self.value``"""
         self._validate_selection(data)
         self.value = data
 
@@ -104,8 +101,7 @@ class MultipleChoiceSetting(EnumStringSetting):
         self._validate_selections(self.value)
 
     def parse(self, data):
-        """Parse and validate ``data`` and store the result at ``self.value``
-        """
+        """Parse and validate ``data`` and store the result at ``self.value``"""
         if data == '':
             self.value = []
             return
@@ -124,25 +120,23 @@ class MultipleChoiceSetting(EnumStringSetting):
                 self.value.append(choice)
 
     def save(self, name, resp):
-        """Save cookie ``name`` in the HTTP reponse obect
-        """
+        """Save cookie ``name`` in the HTTP reponse obect"""
         resp.set_cookie(name, ','.join(self.value), max_age=COOKIE_MAX_AGE)
 
 
 class SetSetting(Setting):
-    """Setting of values of type ``set`` (comma separated string) """
+    """Setting of values of type ``set`` (comma separated string)"""
+
     def _post_init(self):
         if not hasattr(self, 'values'):
             self.values = set()
 
     def get_value(self):
-        """Returns a string with comma separated values.
-        """
+        """Returns a string with comma separated values."""
         return ','.join(self.values)
 
     def parse(self, data):
-        """Parse and validate ``data`` and store the result at ``self.value``
-        """
+        """Parse and validate ``data`` and store the result at ``self.value``"""
         if data == '':
             self.values = set()  # pylint: disable=attribute-defined-outside-init
             return
@@ -159,8 +153,7 @@ class SetSetting(Setting):
         self.values = set(elements)  # pylint: disable=attribute-defined-outside-init
 
     def save(self, name, resp):
-        """Save cookie ``name`` in the HTTP reponse obect
-        """
+        """Save cookie ``name`` in the HTTP reponse obect"""
         resp.set_cookie(name, ','.join(self.values), max_age=COOKIE_MAX_AGE)
 
 
@@ -172,8 +165,7 @@ class SearchLanguageSetting(EnumStringSetting):
             raise ValidationException('Invalid language code: "{0}"'.format(selection))
 
     def parse(self, data):
-        """Parse and validate ``data`` and store the result at ``self.value``
-        """
+        """Parse and validate ``data`` and store the result at ``self.value``"""
         if data not in self.choices and data != self.value:  # pylint: disable=no-member
             # hack to give some backwards compatibility with old language cookies
             data = str(data).replace('_', '-')
@@ -199,8 +191,7 @@ class MapSetting(Setting):
             raise ValidationException('Invalid default value')
 
     def parse(self, data):
-        """Parse and validate ``data`` and store the result at ``self.value``
-        """
+        """Parse and validate ``data`` and store the result at ``self.value``"""
         # pylint: disable=no-member
         if data not in self.map:
             raise ValidationException('Invalid choice: {0}'.format(data))
@@ -208,14 +199,13 @@ class MapSetting(Setting):
         self.key = data  # pylint: disable=attribute-defined-outside-init
 
     def save(self, name, resp):
-        """Save cookie ``name`` in the HTTP reponse obect
-        """
+        """Save cookie ``name`` in the HTTP reponse obect"""
         if hasattr(self, 'key'):
             resp.set_cookie(name, self.key, max_age=COOKIE_MAX_AGE)
 
 
 class SwitchableSetting(Setting):
-    """ Base class for settings that can be turned on && off"""
+    """Base class for settings that can be turned on && off"""
 
     def _post_init(self):
         self.disabled = set()
@@ -244,7 +234,7 @@ class SwitchableSetting(Setting):
 
         items = self.transform_form_items(items)
         self.disabled = set()  # pylint: disable=attribute-defined-outside-init
-        self.enabled = set()   # pylint: disable=attribute-defined-outside-init
+        self.enabled = set()  # pylint: disable=attribute-defined-outside-init
         for choice in self.choices:  # pylint: disable=no-member
             if choice['default_on']:
                 if choice['id'] in items:
@@ -254,8 +244,7 @@ class SwitchableSetting(Setting):
                     self.enabled.add(choice['id'])
 
     def save(self, resp):  # pylint: disable=arguments-differ
-        """Save cookie in the HTTP reponse obect
-        """
+        """Save cookie in the HTTP reponse obect"""
         resp.set_cookie('disabled_{0}'.format(self.value), ','.join(self.disabled), max_age=COOKIE_MAX_AGE)
         resp.set_cookie('enabled_{0}'.format(self.value), ','.join(self.enabled), max_age=COOKIE_MAX_AGE)
 
@@ -289,7 +278,7 @@ class EnginesSetting(SwitchableSetting):
         self.choices = transformed_choices
 
     def transform_form_items(self, items):
-        return [item[len('engine_'):].replace('_', ' ').replace('  ', '__') for item in items]
+        return [item[len('engine_') :].replace('_', ' ').replace('  ', '__') for item in items]
 
     def transform_values(self, values):
         if len(values) == 1 and next(iter(values)) == '':
@@ -315,7 +304,7 @@ class PluginsSetting(SwitchableSetting):
         self.choices = transformed_choices
 
     def transform_form_items(self, items):
-        return [item[len('plugin_'):] for item in items]
+        return [item[len('plugin_') :] for item in items]
 
 
 class Preferences:
@@ -468,19 +457,18 @@ class Preferences:
                     continue
                 self.key_value_settings[user_setting_name].parse(user_setting)
             elif user_setting_name == 'disabled_engines':
-                self.engines.parse_cookie((input_data.get('disabled_engines', ''),
-                                           input_data.get('enabled_engines', '')))
+                self.engines.parse_cookie(
+                    (input_data.get('disabled_engines', ''), input_data.get('enabled_engines', ''))
+                )
             elif user_setting_name == 'disabled_plugins':
-                self.plugins.parse_cookie((input_data.get('disabled_plugins', ''),
-                                           input_data.get('enabled_plugins', '')))
+                self.plugins.parse_cookie(
+                    (input_data.get('disabled_plugins', ''), input_data.get('enabled_plugins', ''))
+                )
             elif user_setting_name == 'tokens':
                 self.tokens.parse(user_setting)
-            elif not any(user_setting_name.startswith(x) for x in [
-                    'enabled_',
-                    'disabled_',
-                    'engine_',
-                    'category_',
-                    'plugin_']):
+            elif not any(
+                user_setting_name.startswith(x) for x in ['enabled_', 'disabled_', 'engine_', 'category_', 'plugin_']
+            ):
                 self.unknown_params[user_setting_name] = user_setting
 
     def parse_form(self, input_data):
@@ -494,7 +482,7 @@ class Preferences:
             elif user_setting_name.startswith('engine_'):
                 disabled_engines.append(user_setting_name)
             elif user_setting_name.startswith('category_'):
-                enabled_categories.append(user_setting_name[len('category_'):])
+                enabled_categories.append(user_setting_name[len('category_') :])
             elif user_setting_name.startswith('plugin_'):
                 disabled_plugins.append(user_setting_name)
             elif user_setting_name == 'tokens':
@@ -507,8 +495,7 @@ class Preferences:
 
     # cannot be used in case of engines or plugins
     def get_value(self, user_setting_name):
-        """Returns the value for ``user_setting_name``
-        """
+        """Returns the value for ``user_setting_name``"""
         ret_val = None
         if user_setting_name in self.key_value_settings:
             ret_val = self.key_value_settings[user_setting_name].get_value()
@@ -517,8 +504,7 @@ class Preferences:
         return ret_val
 
     def save(self, resp):
-        """Save cookie in the HTTP reponse obect
-        """
+        """Save cookie in the HTTP reponse obect"""
         for user_setting_name, user_setting in self.key_value_settings.items():
             # pylint: disable=unnecessary-dict-index-lookup
             if self.key_value_settings[user_setting_name].locked:
@@ -544,8 +530,7 @@ class Preferences:
 
 
 def is_locked(setting_name):
-    """Checks if a given setting name is locked by settings.yml
-    """
+    """Checks if a given setting name is locked by settings.yml"""
     if 'preferences' not in settings:
         return False
     if 'lock' not in settings['preferences']:
diff --git a/searx/query.py b/searx/query.py
index 7f252e93f..b7f64fe82 100644
--- a/searx/query.py
+++ b/searx/query.py
@@ -40,7 +40,6 @@ class QueryPartParser(ABC):
 
 
 class TimeoutParser(QueryPartParser):
-
     @staticmethod
     def check(raw_value):
         return raw_value[0] == '<'
@@ -70,7 +69,6 @@ class TimeoutParser(QueryPartParser):
 
 
 class LanguageParser(QueryPartParser):
-
     @staticmethod
     def check(raw_value):
         return raw_value[0] == ':'
@@ -92,11 +90,9 @@ class LanguageParser(QueryPartParser):
             # if correct language-code is found
             # set it as new search-language
 
-            if (value == lang_id
-                or value == lang_name
-                or value == english_name
-                or value.replace('-', ' ') == country)\
-               and value not in self.raw_text_query.languages:
+            if (
+                value == lang_id or value == lang_name or value == english_name or value.replace('-', ' ') == country
+            ) and value not in self.raw_text_query.languages:
                 found = True
                 lang_parts = lang_id.split('-')
                 if len(lang_parts) == 2:
@@ -152,7 +148,6 @@ class LanguageParser(QueryPartParser):
 
 
 class ExternalBangParser(QueryPartParser):
-
     @staticmethod
     def check(raw_value):
         return raw_value.startswith('!!')
@@ -180,7 +175,6 @@ class ExternalBangParser(QueryPartParser):
 
 
 class BangParser(QueryPartParser):
-
     @staticmethod
     def check(raw_value):
         return raw_value[0] == '!' or raw_value[0] == '?'
@@ -208,9 +202,11 @@ class BangParser(QueryPartParser):
         if value in categories:
             # using all engines for that search, which
             # are declared under that categorie name
-            self.raw_text_query.enginerefs.extend(EngineRef(engine.name, value)
-                                                  for engine in categories[value]
-                                                  if (engine.name, value) not in self.raw_text_query.disabled_engines)
+            self.raw_text_query.enginerefs.extend(
+                EngineRef(engine.name, value)
+                for engine in categories[value]
+                if (engine.name, value) not in self.raw_text_query.disabled_engines
+            )
             return True
 
         return False
@@ -246,7 +242,7 @@ class RawTextQuery:
         TimeoutParser,  # this force the timeout
         LanguageParser,  # this force a language
         ExternalBangParser,  # external bang (must be before BangParser)
-        BangParser  # this force a engine or category
+        BangParser,  # this force a engine or category
     ]
 
     def __init__(self, query, disabled_engines):
@@ -281,8 +277,7 @@ class RawTextQuery:
 
         for i, query_part in enumerate(raw_query_parts):
             # part does only contain spaces, skip
-            if query_part.isspace()\
-               or query_part == '':
+            if query_part.isspace() or query_part == '':
                 continue
 
             # parse special commands
@@ -324,14 +319,16 @@ class RawTextQuery:
         return self.getFullQuery()
 
     def __repr__(self):
-        return f"<{self.__class__.__name__} " \
-               + f"query={self.query!r} " \
-               + f"disabled_engines={self.disabled_engines!r}\n  " \
-               + f"languages={self.languages!r} " \
-               + f"timeout_limit={self.timeout_limit!r} "\
-               + f"external_bang={self.external_bang!r} " \
-               + f"specific={self.specific!r} " \
-               + f"enginerefs={self.enginerefs!r}\n  " \
-               + f"autocomplete_list={self.autocomplete_list!r}\n  " \
-               + f"query_parts={self.query_parts!r}\n  " \
-               + f"user_query_parts={self.user_query_parts!r} >"
+        return (
+            f"<{self.__class__.__name__} "
+            + f"query={self.query!r} "
+            + f"disabled_engines={self.disabled_engines!r}\n  "
+            + f"languages={self.languages!r} "
+            + f"timeout_limit={self.timeout_limit!r} "
+            + f"external_bang={self.external_bang!r} "
+            + f"specific={self.specific!r} "
+            + f"enginerefs={self.enginerefs!r}\n  "
+            + f"autocomplete_list={self.autocomplete_list!r}\n  "
+            + f"query_parts={self.query_parts!r}\n  "
+            + f"user_query_parts={self.user_query_parts!r} >"
+        )
diff --git a/searx/results.py b/searx/results.py
index 10a26aa3f..6ab751c56 100644
--- a/searx/results.py
+++ b/searx/results.py
@@ -47,12 +47,8 @@ def compare_urls(url_a, url_b):
         return False
 
     # remove / from the end of the url if required
-    path_a = url_a.path[:-1]\
-        if url_a.path.endswith('/')\
-        else url_a.path
-    path_b = url_b.path[:-1]\
-        if url_b.path.endswith('/')\
-        else url_b.path
+    path_a = url_a.path[:-1] if url_a.path.endswith('/') else url_a.path
+    path_b = url_b.path[:-1] if url_b.path.endswith('/') else url_b.path
 
     return unquote(path_a) == unquote(path_b)
 
@@ -83,8 +79,9 @@ def merge_two_infoboxes(infobox1, infobox2):
             parsed_url2 = urlparse(url2.get('url', ''))
             entity_url2 = url2.get('entity')
             for url1 in urls1:
-                if (entity_url2 is not None and url1.get('entity') == entity_url2)\
-                   or compare_urls(urlparse(url1.get('url', '')), parsed_url2):
+                if (entity_url2 is not None and url1.get('entity') == entity_url2) or compare_urls(
+                    urlparse(url1.get('url', '')), parsed_url2
+                ):
                     unique_url = False
                     break
             if unique_url:
@@ -115,8 +112,7 @@ def merge_two_infoboxes(infobox1, infobox2):
                 attributeSet.add(entity)
 
         for attribute in infobox2.get('attributes', []):
-            if attribute.get('label') not in attributeSet\
-               and attribute.get('entity') not in attributeSet:
+            if attribute.get('label') not in attributeSet and attribute.get('entity') not in attributeSet:
                 attributes1.append(attribute)
 
     if 'content' in infobox2:
@@ -144,9 +140,22 @@ def result_score(result):
 class ResultContainer:
     """docstring for ResultContainer"""
 
-    __slots__ = '_merged_results', 'infoboxes', 'suggestions', 'answers', 'corrections', '_number_of_results',\
-                '_closed', 'paging', 'unresponsive_engines', 'timings', 'redirect_url', 'engine_data', 'on_result',\
-                '_lock'
+    __slots__ = (
+        '_merged_results',
+        'infoboxes',
+        'suggestions',
+        'answers',
+        'corrections',
+        '_number_of_results',
+        '_closed',
+        'paging',
+        'unresponsive_engines',
+        'timings',
+        'redirect_url',
+        'engine_data',
+        'on_result',
+        '_lock',
+    )
 
     def __init__(self):
         super().__init__()
@@ -208,8 +217,7 @@ class ResultContainer:
         if engine_name in engines:
             histogram_observe(standard_result_count, 'engine', engine_name, 'result', 'count')
 
-        if not self.paging and standard_result_count > 0 and engine_name in engines\
-           and engines[engine_name].paging:
+        if not self.paging and standard_result_count > 0 and engine_name in engines and engines[engine_name].paging:
             self.paging = True
 
     def _merge_infobox(self, infobox):
@@ -248,8 +256,7 @@ class ResultContainer:
         return True
 
     def _normalize_url_result(self, result):
-        """Return True if the result is valid
-        """
+        """Return True if the result is valid"""
         result['parsed_url'] = urlparse(result['url'])
 
         # if the result has no scheme, use http as default
@@ -280,8 +287,9 @@ class ResultContainer:
         for merged_result in self._merged_results:
             if 'parsed_url' not in merged_result:
                 continue
-            if compare_urls(result['parsed_url'], merged_result['parsed_url'])\
-               and result_template == merged_result.get('template'):
+            if compare_urls(result['parsed_url'], merged_result['parsed_url']) and result_template == merged_result.get(
+                'template'
+            ):
                 if result_template != 'images.html':
                     # not an image, same template, same url : it's a duplicate
                     return merged_result
@@ -294,8 +302,7 @@ class ResultContainer:
 
     def __merge_duplicated_http_result(self, duplicated, result, position):
         # using content with more text
-        if result_content_len(result.get('content', '')) >\
-                result_content_len(duplicated.get('content', '')):
+        if result_content_len(result.get('content', '')) > result_content_len(duplicated.get('content', '')):
             duplicated['content'] = result['content']
 
         # merge all result's parameters not found in duplicate
@@ -341,18 +348,20 @@ class ResultContainer:
             res['category'] = engine.categories[0] if len(engine.categories) > 0 else ''
 
             # FIXME : handle more than one category per engine
-            category = res['category']\
-                + ':' + res.get('template', '')\
-                + ':' + ('img_src' if 'img_src' in res or 'thumbnail' in res else '')
+            category = (
+                res['category']
+                + ':'
+                + res.get('template', '')
+                + ':'
+                + ('img_src' if 'img_src' in res or 'thumbnail' in res else '')
+            )
 
-            current = None if category not in categoryPositions\
-                else categoryPositions[category]
+            current = None if category not in categoryPositions else categoryPositions[category]
 
             # group with previous results using the same category
             # if the group can accept more result and is not too far
             # from the current position
-            if current is not None and (current['count'] > 0)\
-                    and (len(gresults) - current['index'] < 20):
+            if current is not None and (current['count'] > 0) and (len(gresults) - current['index'] < 20):
                 # group with the previous results using
                 # the same category with this one
                 index = current['index']
diff --git a/searx/search/__init__.py b/searx/search/__init__.py
index 0a3c5b3ac..d66f3362d 100644
--- a/searx/search/__init__.py
+++ b/searx/search/__init__.py
@@ -123,8 +123,11 @@ class Search:
             # Max & user query: From user query except if above max
             actual_timeout = min(query_timeout, max_request_timeout)
 
-        logger.debug("actual_timeout={0} (default_timeout={1}, ?timeout_limit={2}, max_request_timeout={3})"
-                     .format(actual_timeout, default_timeout, query_timeout, max_request_timeout))
+        logger.debug(
+            "actual_timeout={0} (default_timeout={1}, ?timeout_limit={2}, max_request_timeout={3})".format(
+                actual_timeout, default_timeout, query_timeout, max_request_timeout
+            )
+        )
 
         return requests, actual_timeout
 
diff --git a/searx/search/checker/__main__.py b/searx/search/checker/__main__.py
index 4ce4ca76b..1311288f3 100644
--- a/searx/search/checker/__main__.py
+++ b/searx/search/checker/__main__.py
@@ -37,12 +37,12 @@ else:
 stdout = io.TextIOWrapper(
     # pylint: disable=consider-using-with
     open(sys.stdout.fileno(), 'wb', 0),
-    write_through=True
+    write_through=True,
 )
 stderr = io.TextIOWrapper(
     # pylint: disable=consider-using-with
-    open(sys.stderr.fileno(), 'wb', 0)
-    , write_through=True
+    open(sys.stderr.fileno(), 'wb', 0),
+    write_through=True,
 )
 
 
@@ -91,12 +91,21 @@ def run(engine_name_list, verbose):
 # call by setup.py
 def main():
     parser = argparse.ArgumentParser(description='Check searx engines.')
-    parser.add_argument('engine_name_list', metavar='engine name', type=str, nargs='*',
-                        help='engines name or shortcut list. Empty for all engines.')
-    parser.add_argument('--verbose', '-v',
-                        action='store_true', dest='verbose',
-                        help='Display details about the test results',
-                        default=False)
+    parser.add_argument(
+        'engine_name_list',
+        metavar='engine name',
+        type=str,
+        nargs='*',
+        help='engines name or shortcut list. Empty for all engines.',
+    )
+    parser.add_argument(
+        '--verbose',
+        '-v',
+        action='store_true',
+        dest='verbose',
+        help='Display details about the test results',
+        default=False,
+    )
     args = parser.parse_args()
     run(args.engine_name_list, args.verbose)
 
diff --git a/searx/search/checker/background.py b/searx/search/checker/background.py
index d9f11a71c..ff005dd91 100644
--- a/searx/search/checker/background.py
+++ b/searx/search/checker/background.py
@@ -23,10 +23,12 @@ running = threading.Lock()
 def _get_interval(every, error_msg):
     if isinstance(every, int):
         every = (every, every)
-    if not isinstance(every, (tuple, list))\
-       or len(every) != 2\
-       or not isinstance(every[0], int)\
-       or not isinstance(every[1], int):
+    if (
+        not isinstance(every, (tuple, list))
+        or len(every) != 2
+        or not isinstance(every[0], int)
+        or not isinstance(every[1], int)
+    ):
         raise SearxSettingsException(error_msg, None)
     return every
 
@@ -50,14 +52,11 @@ def _set_result(result, include_timestamp=True):
 
 
 def run():
-    if not running.acquire(blocking=False): # pylint: disable=consider-using-with
+    if not running.acquire(blocking=False):  # pylint: disable=consider-using-with
         return
     try:
         logger.info('Starting checker')
-        result = {
-            'status': 'ok',
-            'engines': {}
-        }
+        result = {'status': 'ok', 'engines': {}}
         for name, processor in PROCESSORS.items():
             logger.debug('Checking %s engine', name)
             checker = Checker(processor)
diff --git a/searx/search/checker/impl.py b/searx/search/checker/impl.py
index e68248c0e..c0dd966d0 100644
--- a/searx/search/checker/impl.py
+++ b/searx/search/checker/impl.py
@@ -74,17 +74,23 @@ def _download_and_check_if_image(image_url: str) -> bool:
         try:
             # use "image_proxy" (avoid HTTP/2)
             network.set_context_network_name('image_proxy')
-            stream = network.stream('GET', image_url, timeout=10.0, allow_redirects=True, headers={
-                'User-Agent': gen_useragent(),
-                'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
-                'Accept-Language': 'en-US;q=0.5,en;q=0.3',
-                'Accept-Encoding': 'gzip, deflate, br',
-                'DNT': '1',
-                'Connection': 'keep-alive',
-                'Upgrade-Insecure-Requests': '1',
-                'Sec-GPC': '1',
-                'Cache-Control': 'max-age=0'
-            })
+            stream = network.stream(
+                'GET',
+                image_url,
+                timeout=10.0,
+                allow_redirects=True,
+                headers={
+                    'User-Agent': gen_useragent(),
+                    'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
+                    'Accept-Language': 'en-US;q=0.5,en;q=0.3',
+                    'Accept-Encoding': 'gzip, deflate, br',
+                    'DNT': '1',
+                    'Connection': 'keep-alive',
+                    'Upgrade-Insecure-Requests': '1',
+                    'Sec-GPC': '1',
+                    'Cache-Control': 'max-age=0',
+                },
+            )
             r = next(stream)
             r.close()
             if r.status_code == 200:
@@ -104,8 +110,7 @@ def _download_and_check_if_image(image_url: str) -> bool:
 
 
 def _is_url_image(image_url) -> bool:
-    """Normalize image_url
-    """
+    """Normalize image_url"""
     if not isinstance(image_url, str):
         return False
 
@@ -131,8 +136,9 @@ def _search_query_to_dict(search_query: SearchQuery) -> typing.Dict[str, typing.
     }
 
 
-def _search_query_diff(sq1: SearchQuery, sq2: SearchQuery)\
-        -> typing.Tuple[typing.Dict[str, typing.Any], typing.Dict[str, typing.Any]]:
+def _search_query_diff(
+    sq1: SearchQuery, sq2: SearchQuery
+) -> typing.Tuple[typing.Dict[str, typing.Any], typing.Dict[str, typing.Any]]:
     param1 = _search_query_to_dict(sq1)
     param2 = _search_query_to_dict(sq2)
     common = {}
@@ -182,11 +188,9 @@ class ResultContainerTests:
 
     __slots__ = 'test_name', 'search_query', 'result_container', 'languages', 'stop_test', 'test_results'
 
-    def __init__(self,
-                 test_results: TestResults,
-                 test_name: str,
-                 search_query: SearchQuery,
-                 result_container: ResultContainer):
+    def __init__(
+        self, test_results: TestResults, test_name: str, search_query: SearchQuery, result_container: ResultContainer
+    ):
         self.test_name = test_name
         self.search_query = search_query
         self.result_container = result_container
@@ -326,10 +330,9 @@ class CheckerTests:
 
     __slots__ = 'test_results', 'test_name', 'result_container_tests_list'
 
-    def __init__(self,
-                 test_results: TestResults,
-                 test_name: str,
-                 result_container_tests_list: typing.List[ResultContainerTests]):
+    def __init__(
+        self, test_results: TestResults, test_name: str, result_container_tests_list: typing.List[ResultContainerTests]
+    ):
         self.test_results = test_results
         self.test_name = test_name
         self.result_container_tests_list = result_container_tests_list
@@ -342,14 +345,17 @@ class CheckerTests:
             for i, urls_i in enumerate(urls_list):
                 for j, urls_j in enumerate(urls_list):
                     if i < j and urls_i == urls_j:
-                        common, diff = _search_query_diff(self.result_container_tests_list[i].search_query,
-                                                          self.result_container_tests_list[j].search_query)
+                        common, diff = _search_query_diff(
+                            self.result_container_tests_list[i].search_query,
+                            self.result_container_tests_list[j].search_query,
+                        )
                         common_str = ' '.join(['{}={!r}'.format(k, v) for k, v in common.items()])
-                        diff1_str = ', ' .join(['{}={!r}'.format(k, v1) for (k, (v1, v2)) in diff.items()])
-                        diff2_str = ', ' .join(['{}={!r}'.format(k, v2) for (k, (v1, v2)) in diff.items()])
-                        self.test_results.add_error(self.test_name,
-                                                    'results are identitical for {} and {} ({})'
-                                                    .format(diff1_str, diff2_str, common_str))
+                        diff1_str = ', '.join(['{}={!r}'.format(k, v1) for (k, (v1, v2)) in diff.items()])
+                        diff2_str = ', '.join(['{}={!r}'.format(k, v2) for (k, (v1, v2)) in diff.items()])
+                        self.test_results.add_error(
+                            self.test_name,
+                            'results are identitical for {} and {} ({})'.format(diff1_str, diff2_str, common_str),
+                        )
 
 
 class Checker:
@@ -395,9 +401,10 @@ class Checker:
         elif isinstance(method, types.FunctionType):
             method(*args)
         else:
-            self.test_results.add_error(obj.test_name,
-                                        'method {!r} ({}) not found for {}'
-                                        .format(method, method.__class__.__name__, obj.__class__.__name__))
+            self.test_results.add_error(
+                obj.test_name,
+                'method {!r} ({}) not found for {}'.format(method, method.__class__.__name__, obj.__class__.__name__),
+            )
 
     def call_tests(self, obj, test_descriptions):
         for test_description in test_descriptions:
diff --git a/searx/search/models.py b/searx/search/models.py
index e48cb3611..ff5897966 100644
--- a/searx/search/models.py
+++ b/searx/search/models.py
@@ -25,19 +25,30 @@ class EngineRef:
 class SearchQuery:
     """container for all the search parameters (query, language, etc...)"""
 
-    __slots__ = 'query', 'engineref_list', 'lang', 'safesearch', 'pageno', 'time_range',\
-                'timeout_limit', 'external_bang', 'engine_data'
-
-    def __init__(self,
-                 query: str,
-                 engineref_list: typing.List[EngineRef],
-                 lang: str='all',
-                 safesearch: int=0,
-                 pageno: int=1,
-                 time_range: typing.Optional[str]=None,
-                 timeout_limit: typing.Optional[float]=None,
-                 external_bang: typing.Optional[str]=None,
-                 engine_data: typing.Optional[typing.Dict[str, str]]=None):
+    __slots__ = (
+        'query',
+        'engineref_list',
+        'lang',
+        'safesearch',
+        'pageno',
+        'time_range',
+        'timeout_limit',
+        'external_bang',
+        'engine_data',
+    )
+
+    def __init__(
+        self,
+        query: str,
+        engineref_list: typing.List[EngineRef],
+        lang: str = 'all',
+        safesearch: int = 0,
+        pageno: int = 1,
+        time_range: typing.Optional[str] = None,
+        timeout_limit: typing.Optional[float] = None,
+        external_bang: typing.Optional[str] = None,
+        engine_data: typing.Optional[typing.Dict[str, str]] = None,
+    ):
         self.query = query
         self.engineref_list = engineref_list
         self.lang = lang
@@ -53,20 +64,39 @@ class SearchQuery:
         return list(set(map(lambda engineref: engineref.category, self.engineref_list)))
 
     def __repr__(self):
-        return "SearchQuery({!r}, {!r}, {!r}, {!r}, {!r}, {!r}, {!r}, {!r})".\
-               format(self.query, self.engineref_list, self.lang, self.safesearch,
-                      self.pageno, self.time_range, self.timeout_limit, self.external_bang)
+        return "SearchQuery({!r}, {!r}, {!r}, {!r}, {!r}, {!r}, {!r}, {!r})".format(
+            self.query,
+            self.engineref_list,
+            self.lang,
+            self.safesearch,
+            self.pageno,
+            self.time_range,
+            self.timeout_limit,
+            self.external_bang,
+        )
 
     def __eq__(self, other):
-        return self.query == other.query\
-            and self.engineref_list == other.engineref_list\
-            and self.lang == other.lang\
-            and self.safesearch == other.safesearch\
-            and self.pageno == other.pageno\
-            and self.time_range == other.time_range\
-            and self.timeout_limit == other.timeout_limit\
+        return (
+            self.query == other.query
+            and self.engineref_list == other.engineref_list
+            and self.lang == other.lang
+            and self.safesearch == other.safesearch
+            and self.pageno == other.pageno
+            and self.time_range == other.time_range
+            and self.timeout_limit == other.timeout_limit
             and self.external_bang == other.external_bang
+        )
 
     def __hash__(self):
-        return hash((self.query, tuple(self.engineref_list), self.lang, self.safesearch, self.pageno, self.time_range,
-                     self.timeout_limit, self.external_bang))
+        return hash(
+            (
+                self.query,
+                tuple(self.engineref_list),
+                self.lang,
+                self.safesearch,
+                self.pageno,
+                self.time_range,
+                self.timeout_limit,
+                self.external_bang,
+            )
+        )
diff --git a/searx/search/processors/__init__.py b/searx/search/processors/__init__.py
index 8108f8dfa..966b990ec 100644
--- a/searx/search/processors/__init__.py
+++ b/searx/search/processors/__init__.py
@@ -29,6 +29,7 @@ logger = logger.getChild('search.processors')
 PROCESSORS = {}
 """Cache request processores, stored by *engine-name* (:py:func:`initialize`)"""
 
+
 def get_processor_class(engine_type):
     """Return processor class according to the ``engine_type``"""
     for c in [OnlineProcessor, OfflineProcessor, OnlineDictionaryProcessor, OnlineCurrencyProcessor]:
diff --git a/searx/search/processors/abstract.py b/searx/search/processors/abstract.py
index b5fa063fd..732b55d52 100644
--- a/searx/search/processors/abstract.py
+++ b/searx/search/processors/abstract.py
@@ -19,6 +19,7 @@ from searx.utils import get_engine_from_settings
 logger = logger.getChild('searx.search.processor')
 SUSPENDED_STATUS = {}
 
+
 class SuspendedStatus:
     """Class to handle suspend state."""
 
@@ -39,8 +40,10 @@ class SuspendedStatus:
             # update continuous_errors / suspend_end_time
             self.continuous_errors += 1
             if suspended_time is None:
-                suspended_time = min(settings['search']['max_ban_time_on_fail'],
-                                     self.continuous_errors * settings['search']['ban_time_on_fail'])
+                suspended_time = min(
+                    settings['search']['max_ban_time_on_fail'],
+                    self.continuous_errors * settings['search']['ban_time_on_fail'],
+                )
             self.suspend_end_time = default_timer() + suspended_time
             self.suspend_reason = suspend_reason
             logger.debug('Suspend for %i seconds', suspended_time)
@@ -127,9 +130,9 @@ class EngineProcessor(ABC):
 
     def extend_container_if_suspended(self, result_container):
         if self.suspended_status.is_suspended:
-            result_container.add_unresponsive_engine(self.engine_name,
-                                                     self.suspended_status.suspend_reason,
-                                                     suspended=True)
+            result_container.add_unresponsive_engine(
+                self.engine_name, self.suspended_status.suspend_reason, suspended=True
+            )
             return True
         return False
 
diff --git a/searx/search/processors/offline.py b/searx/search/processors/offline.py
index ec7a4a36e..13f077cb1 100644
--- a/searx/search/processors/offline.py
+++ b/searx/search/processors/offline.py
@@ -23,6 +23,6 @@ class OfflineProcessor(EngineProcessor):
         except ValueError as e:
             # do not record the error
             self.logger.exception('engine {0} : invalid input : {1}'.format(self.engine_name, e))
-        except Exception as e: # pylint: disable=broad-except
+        except Exception as e:  # pylint: disable=broad-except
             self.handle_exception(result_container, e)
             self.logger.exception('engine {0} : exception : {1}'.format(self.engine_name, e))
diff --git a/searx/search/processors/online.py b/searx/search/processors/online.py
index 674ba9c8e..8d8275df1 100644
--- a/searx/search/processors/online.py
+++ b/searx/search/processors/online.py
@@ -66,10 +66,7 @@ class OnlineProcessor(EngineProcessor):
         # create dictionary which contain all
         # informations about the request
         request_args = dict(
-            headers=params['headers'],
-            cookies=params['cookies'],
-            verify=params['verify'],
-            auth=params['auth']
+            headers=params['headers'], cookies=params['cookies'], verify=params['verify'], auth=params['auth']
         )
 
         # max_redirects
@@ -105,10 +102,12 @@ class OnlineProcessor(EngineProcessor):
             status_code = str(response.status_code or '')
             reason = response.reason_phrase or ''
             hostname = response.url.host
-            count_error(self.engine_name,
-                        '{} redirects, maximum: {}'.format(len(response.history), soft_max_redirects),
-                        (status_code, reason, hostname),
-                        secondary=True)
+            count_error(
+                self.engine_name,
+                '{} redirects, maximum: {}'.format(len(response.history), soft_max_redirects),
+                (status_code, reason, hostname),
+                secondary=True,
+            )
 
         return response
 
@@ -147,22 +146,16 @@ class OnlineProcessor(EngineProcessor):
             # requests timeout (connect or read)
             self.handle_exception(result_container, e, suspend=True)
             self.logger.error(
-                "HTTP requests timeout (search duration : {0} s, timeout: {1} s) : {2}"
-                .format(
-                    default_timer() - start_time,
-                    timeout_limit,
-                    e.__class__.__name__
+                "HTTP requests timeout (search duration : {0} s, timeout: {1} s) : {2}".format(
+                    default_timer() - start_time, timeout_limit, e.__class__.__name__
                 )
             )
         except (httpx.HTTPError, httpx.StreamError) as e:
             # other requests exception
             self.handle_exception(result_container, e, suspend=True)
             self.logger.exception(
-                "requests exception (search duration : {0} s, timeout: {1} s) : {2}"
-                .format(
-                    default_timer() - start_time,
-                    timeout_limit,
-                    e
+                "requests exception (search duration : {0} s, timeout: {1} s) : {2}".format(
+                    default_timer() - start_time, timeout_limit, e
                 )
             )
         except SearxEngineCaptchaException as e:
@@ -188,10 +181,9 @@ class OnlineProcessor(EngineProcessor):
 
         if getattr(self.engine, 'paging', False):
             tests['paging'] = {
-                'matrix': {'query': 'time',
-                           'pageno': (1, 2, 3)},
+                'matrix': {'query': 'time', 'pageno': (1, 2, 3)},
                 'result_container': ['not_empty'],
-                'test': ['unique_results']
+                'test': ['unique_results'],
             }
             if 'general' in self.engine.categories:
                 # avoid documentation about HTML tags (<time> and <input type="time">)
@@ -199,10 +191,9 @@ class OnlineProcessor(EngineProcessor):
 
         if getattr(self.engine, 'time_range', False):
             tests['time_range'] = {
-                'matrix': {'query': 'news',
-                           'time_range': (None, 'day')},
+                'matrix': {'query': 'news', 'time_range': (None, 'day')},
                 'result_container': ['not_empty'],
-                'test': ['unique_results']
+                'test': ['unique_results'],
             }
 
         if getattr(self.engine, 'supported_languages', []):
@@ -216,10 +207,6 @@ class OnlineProcessor(EngineProcessor):
             }
 
         if getattr(self.engine, 'safesearch', False):
-            tests['safesearch'] = {
-                'matrix': {'query': 'porn',
-                           'safesearch': (0, 2)},
-                'test': ['unique_results']
-            }
+            tests['safesearch'] = {'matrix': {'query': 'porn', 'safesearch': (0, 2)}, 'test': ['unique_results']}
 
         return tests
diff --git a/searx/search/processors/online_currency.py b/searx/search/processors/online_currency.py
index 4e5c57264..6bd891b1d 100644
--- a/searx/search/processors/online_currency.py
+++ b/searx/search/processors/online_currency.py
@@ -12,11 +12,13 @@ from .online import OnlineProcessor
 
 parser_re = re.compile('.*?(\\d+(?:\\.\\d+)?) ([^.0-9]+) (?:in|to) ([^.0-9]+)', re.I)
 
+
 def normalize_name(name):
     name = name.lower().replace('-', ' ').rstrip('s')
     name = re.sub(' +', ' ', name)
     return unicodedata.normalize('NFKD', name).lower()
 
+
 def name_to_iso4217(name):
     name = normalize_name(name)
     currency = CURRENCIES['names'].get(name, [name])
@@ -24,9 +26,11 @@ def name_to_iso4217(name):
         return currency
     return currency[0]
 
+
 def iso4217_to_name(iso4217, language):
     return CURRENCIES['iso4217'].get(iso4217, {}).get(language, iso4217)
 
+
 class OnlineCurrencyProcessor(OnlineProcessor):
 
     """Processor class used by ``online_currency`` engines."""
diff --git a/searx/search/processors/online_dictionary.py b/searx/search/processors/online_dictionary.py
index 72941d57a..3e7f6ed59 100644
--- a/searx/search/processors/online_dictionary.py
+++ b/searx/search/processors/online_dictionary.py
@@ -11,6 +11,7 @@ from .online import OnlineProcessor
 
 parser_re = re.compile('.*?([a-z]+)-([a-z]+) ([^ ]+)$', re.I)
 
+
 class OnlineDictionaryProcessor(OnlineProcessor):
     """Processor class used by ``online_dictionary`` engines."""
 
@@ -44,10 +45,9 @@ class OnlineDictionaryProcessor(OnlineProcessor):
 
         if getattr(self.engine, 'paging', False):
             tests['translation_paging'] = {
-                'matrix': {'query': 'en-es house',
-                           'pageno': (1, 2, 3)},
+                'matrix': {'query': 'en-es house', 'pageno': (1, 2, 3)},
                 'result_container': ['not_empty', ('one_title_contains', 'house')],
-                'test': ['unique_results']
+                'test': ['unique_results'],
             }
         else:
             tests['translation'] = {
diff --git a/searx/settings_defaults.py b/searx/settings_defaults.py
index db020db7d..9c4711bfc 100644
--- a/searx/settings_defaults.py
+++ b/searx/settings_defaults.py
@@ -53,29 +53,24 @@ SEARX_ENVIRON_VARIABLES = {
 }
 
 
-
 class SettingsValue:
-    """Check and update a setting value
-    """
-
-    def __init__(self,
-                 type_definition: typing.Union[None, typing.Any, typing.Tuple[typing.Any]]=None,
-                 default: typing.Any=None,
-                 environ_name: str=None):
+    """Check and update a setting value"""
+
+    def __init__(
+        self,
+        type_definition: typing.Union[None, typing.Any, typing.Tuple[typing.Any]] = None,
+        default: typing.Any = None,
+        environ_name: str = None,
+    ):
         self.type_definition = (
-            type_definition
-            if type_definition is None or isinstance(type_definition, tuple)
-            else (type_definition,)
+            type_definition if type_definition is None or isinstance(type_definition, tuple) else (type_definition,)
         )
         self.default = default
         self.environ_name = environ_name
 
     @property
     def type_definition_repr(self):
-        types_str = [
-            t.__name__ if isinstance(t, type) else repr(t)
-            for t in self.type_definition
-        ]
+        types_str = [t.__name__ if isinstance(t, type) else repr(t) for t in self.type_definition]
         return ', '.join(types_str)
 
     def check_type_definition(self, value: typing.Any) -> None:
@@ -83,9 +78,7 @@ class SettingsValue:
             return
         type_list = tuple(t for t in self.type_definition if isinstance(t, type))
         if not isinstance(value, type_list):
-            raise ValueError(
-                'The value has to be one of these types/values: {}'.format(
-                    self.type_definition_repr))
+            raise ValueError('The value has to be one of these types/values: {}'.format(self.type_definition_repr))
 
     def __call__(self, value: typing.Any) -> typing.Any:
         if value == _UNDEFINED:
@@ -101,8 +94,7 @@ class SettingsValue:
 
 
 class SettingSublistValue(SettingsValue):
-    """Check the value is a sublist of type definition.
-    """
+    """Check the value is a sublist of type definition."""
 
     def check_type_definition(self, value: typing.Any) -> typing.Any:
         if not isinstance(value, list):
@@ -111,9 +103,9 @@ class SettingSublistValue(SettingsValue):
             if not item in self.type_definition[0]:
                 raise ValueError('{} not in {}'.format(item, self.type_definition))
 
+
 class SettingsDirectoryValue(SettingsValue):
-    """Check and update a setting value that is a directory path
-    """
+    """Check and update a setting value that is a directory path"""
 
     def check_type_definition(self, value: typing.Any) -> typing.Any:
         super().check_type_definition(value)
@@ -159,7 +151,7 @@ SCHEMA = {
         'wiki_url': SettingsValue(str, 'https://github.com/searxng/searxng/wiki'),
     },
     'search': {
-        'safe_search': SettingsValue((0,1,2), 0),
+        'safe_search': SettingsValue((0, 1, 2), 0),
         'autocomplete': SettingsValue(str, ''),
         'default_lang': SettingsValue(tuple(LANGUAGE_CODES + ['']), ''),
         'languages': SettingSublistValue(LANGUAGE_CODES, LANGUAGE_CODES),
@@ -168,7 +160,7 @@ SCHEMA = {
         'formats': SettingsValue(list, OUTPUT_FORMATS),
     },
     'server': {
-        'port': SettingsValue((int,str), 8888, 'SEARXNG_PORT'),
+        'port': SettingsValue((int, str), 8888, 'SEARXNG_PORT'),
         'bind_address': SettingsValue(str, '127.0.0.1', 'SEARXNG_BIND_ADDRESS'),
         'secret_key': SettingsValue(str, environ_name='SEARXNG_SECRET'),
         'base_url': SettingsValue((False, str), False),
@@ -213,8 +205,7 @@ SCHEMA = {
         # Tor configuration
         'using_tor_proxy': SettingsValue(bool, False),
         'extra_proxy_timeout': SettingsValue(int, 0),
-        'networks': {
-        },
+        'networks': {},
     },
     'plugins': SettingsValue(list, []),
     'enabled_plugins': SettingsValue((None, list), None),
@@ -222,10 +213,10 @@ SCHEMA = {
         'off_when_debug': SettingsValue(bool, True),
     },
     'engines': SettingsValue(list, []),
-    'doi_resolvers': {
-    },
+    'doi_resolvers': {},
 }
 
+
 def settings_set_defaults(settings):
     # compatibility with searx variables
     for searx, searxng in SEARX_ENVIRON_VARIABLES.items():
diff --git a/searx/settings_loader.py b/searx/settings_loader.py
index f688be8ba..14ca8b4aa 100644
--- a/searx/settings_loader.py
+++ b/searx/settings_loader.py
@@ -125,8 +125,7 @@ def load_settings(load_user_setttings=True):
     user_settings_path = get_user_settings_path()
     if user_settings_path is None or not load_user_setttings:
         # no user settings
-        return (load_yaml(default_settings_path),
-                'load the default settings from {}'.format(default_settings_path))
+        return (load_yaml(default_settings_path), 'load the default settings from {}'.format(default_settings_path))
 
     # user settings
     user_settings = load_yaml(user_settings_path)
@@ -134,10 +133,12 @@ def load_settings(load_user_setttings=True):
         # the user settings are merged with the default configuration
         default_settings = load_yaml(default_settings_path)
         update_settings(default_settings, user_settings)
-        return (default_settings,
-                'merge the default settings ( {} ) and the user setttings ( {} )'
-                .format(default_settings_path, user_settings_path))
+        return (
+            default_settings,
+            'merge the default settings ( {} ) and the user setttings ( {} )'.format(
+                default_settings_path, user_settings_path
+            ),
+        )
 
     # the user settings, fully replace the default configuration
-    return (user_settings,
-            'load the user settings from {}'.format(user_settings_path))
+    return (user_settings, 'load the user settings from {}'.format(user_settings_path))
diff --git a/searx/shared/__init__.py b/searx/shared/__init__.py
index cbe24d239..98c9a11c2 100644
--- a/searx/shared/__init__.py
+++ b/searx/shared/__init__.py
@@ -9,6 +9,7 @@ try:
 except:
     # no uwsgi
     from .shared_simple import SimpleSharedDict as SharedDict, schedule
+
     logger.info('Use shared_simple implementation')
 else:
     try:
@@ -17,15 +18,19 @@ else:
             raise Exception()
     except:
         # uwsgi.ini configuration problem: disable all scheduling
-        logger.error('uwsgi.ini configuration error, add this line to your uwsgi.ini\n'
-                     'cache2 = name=searxcache,items=2000,blocks=2000,blocksize=4096,bitmap=1')
+        logger.error(
+            'uwsgi.ini configuration error, add this line to your uwsgi.ini\n'
+            'cache2 = name=searxcache,items=2000,blocks=2000,blocksize=4096,bitmap=1'
+        )
         from .shared_simple import SimpleSharedDict as SharedDict
 
         def schedule(delay, func, *args):
             return False
+
     else:
         # uwsgi
         from .shared_uwsgi import UwsgiCacheSharedDict as SharedDict, schedule
+
         logger.info('Use shared_uwsgi implementation')
 
 storage = SharedDict()
diff --git a/searx/shared/shared_abstract.py b/searx/shared/shared_abstract.py
index b1c72aabe..b4b15bea6 100644
--- a/searx/shared/shared_abstract.py
+++ b/searx/shared/shared_abstract.py
@@ -3,7 +3,6 @@ from abc import ABC, abstractmethod
 
 
 class SharedDict(ABC):
-
     @abstractmethod
     def get_int(self, key):
         pass
diff --git a/searx/shared/shared_simple.py b/searx/shared/shared_simple.py
index 48d8cb822..0bf13a2a6 100644
--- a/searx/shared/shared_simple.py
+++ b/searx/shared/shared_simple.py
@@ -7,7 +7,7 @@ from . import shared_abstract
 
 class SimpleSharedDict(shared_abstract.SharedDict):
 
-    __slots__ = 'd',
+    __slots__ = ('d',)
 
     def __init__(self):
         self.d = {}
diff --git a/searx/shared/shared_uwsgi.py b/searx/shared/shared_uwsgi.py
index a6dba9f59..592e24a4b 100644
--- a/searx/shared/shared_uwsgi.py
+++ b/searx/shared/shared_uwsgi.py
@@ -9,7 +9,6 @@ _last_signal = 10
 
 
 class UwsgiCacheSharedDict(shared_abstract.SharedDict):
-
     def get_int(self, key):
         value = uwsgi.cache_get(key)
         if value is None:
diff --git a/searx/unixthreadname.py b/searx/unixthreadname.py
index 0f1f54936..3c2a68917 100644
--- a/searx/unixthreadname.py
+++ b/searx/unixthreadname.py
@@ -11,10 +11,12 @@ except ImportError:
     pass
 else:
     import threading
+
     old_thread_init = threading.Thread.__init__
 
     def new_thread_init(self, *args, **kwargs):
         # pylint: disable=protected-access, disable=c-extension-no-member
         old_thread_init(self, *args, **kwargs)
         setproctitle.setthreadtitle(self._name)
+
     threading.Thread.__init__ = new_thread_init
diff --git a/searx/utils.py b/searx/utils.py
index 163892e93..d44bb73ea 100644
--- a/searx/utils.py
+++ b/searx/utils.py
@@ -23,8 +23,7 @@ from searx import logger
 
 logger = logger.getChild('utils')
 
-blocked_tags = ('script',
-                'style')
+blocked_tags = ('script', 'style')
 
 ecma_unescape4_re = re.compile(r'%u([0-9a-fA-F]{4})', re.UNICODE)
 ecma_unescape2_re = re.compile(r'%([0-9a-fA-F]{2})', re.UNICODE)
@@ -43,8 +42,8 @@ NOTSET = NotSetClass()
 def searx_useragent():
     """Return the searx User Agent"""
     return 'searx/{searx_version} {suffix}'.format(
-           searx_version=VERSION_TAG,
-           suffix=settings['outgoing']['useragent_suffix']).strip()
+        searx_version=VERSION_TAG, suffix=settings['outgoing']['useragent_suffix']
+    ).strip()
 
 
 def gen_useragent(os=None):
@@ -60,7 +59,6 @@ class HTMLTextExtractorException(Exception):
 
 
 class HTMLTextExtractor(HTMLParser):  # pylint: disable=W0223  # (see https://bugs.python.org/issue31844)
-
     def __init__(self):
         HTMLParser.__init__(self)
         self.result = []
@@ -135,10 +133,10 @@ def html_to_text(html_str):
 def extract_text(xpath_results, allow_none=False):
     """Extract text from a lxml result
 
-      * if xpath_results is list, extract the text from each result and concat the list
-      * if xpath_results is a xml element, extract all the text node from it
-        ( text_content() method from lxml )
-      * if xpath_results is a string element, then it's already done
+    * if xpath_results is list, extract the text from each result and concat the list
+    * if xpath_results is a xml element, extract all the text node from it
+      ( text_content() method from lxml )
+    * if xpath_results is a string element, then it's already done
     """
     if isinstance(xpath_results, list):
         # it's list of result : concat everything using recursive call
@@ -148,9 +146,7 @@ def extract_text(xpath_results, allow_none=False):
         return result.strip()
     elif isinstance(xpath_results, ElementBase):
         # it's a element
-        text = html.tostring(
-            xpath_results, encoding='unicode', method='text', with_tail=False
-        )
+        text = html.tostring(xpath_results, encoding='unicode', method='text', with_tail=False)
         text = text.strip().replace('\n', ' ')
         return ' '.join(text.split())
     elif isinstance(xpath_results, (_ElementStringResult, _ElementUnicodeResult, str, Number, bool)):
@@ -344,7 +340,7 @@ def is_valid_lang(lang):
     """
     if isinstance(lang, bytes):
         lang = lang.decode()
-    is_abbr = (len(lang) == 2)
+    is_abbr = len(lang) == 2
     lang = lang.lower()
     if is_abbr:
         for l in language_codes:
diff --git a/searx/version.py b/searx/version.py
index ac42834d9..9b3fcc35e 100644
--- a/searx/version.py
+++ b/searx/version.py
@@ -81,16 +81,12 @@ def get_git_version():
 
     # add "-dirty" suffix if there are uncommited changes except searx/settings.yml
     try:
-        subprocess_run(
-            "git diff --quiet -- . ':!searx/settings.yml' ':!utils/brand.env'"
-        )
+        subprocess_run("git diff --quiet -- . ':!searx/settings.yml' ':!utils/brand.env'")
     except subprocess.CalledProcessError as e:
         if e.returncode == 1:
             git_version += "-dirty"
         else:
-            logger.warning(
-                '"%s" returns an unexpected return code %i', e.returncode, e.cmd
-            )
+            logger.warning('"%s" returns an unexpected return code %i', e.returncode, e.cmd)
     return git_version, tag_version
 
 
@@ -125,9 +121,7 @@ VERSION_TAG = "{VERSION_TAG}"
 GIT_URL = "{GIT_URL}"
 GIT_BRANCH = "{GIT_BRANCH}"
 """
-        with open(
-                os.path.join(os.path.dirname(__file__), "version_frozen.py"),
-                "w", encoding="utf8") as f:
+        with open(os.path.join(os.path.dirname(__file__), "version_frozen.py"), "w", encoding="utf8") as f:
             f.write(python_code)
             print(f"{f.name} created")
     else:
diff --git a/searx/webadapter.py b/searx/webadapter.py
index 58cbf1d90..4fd18cee9 100644
--- a/searx/webadapter.py
+++ b/searx/webadapter.py
@@ -15,8 +15,9 @@ def deduplicate_engineref_list(engineref_list: List[EngineRef]) -> List[EngineRe
     return list(engineref_dict.values())
 
 
-def validate_engineref_list(engineref_list: List[EngineRef], preferences: Preferences)\
-        -> Tuple[List[EngineRef], List[EngineRef], List[EngineRef]]:
+def validate_engineref_list(
+    engineref_list: List[EngineRef], preferences: Preferences
+) -> Tuple[List[EngineRef], List[EngineRef], List[EngineRef]]:
     """Validate query_engines according to the preferences
 
     Returns:
@@ -154,9 +155,11 @@ def get_selected_categories(preferences: Preferences, form: Optional[Dict[str, s
 def get_engineref_from_category_list(category_list: List[str], disabled_engines: List[str]) -> List[EngineRef]:
     result = []
     for categ in category_list:
-        result.extend(EngineRef(engine.name, categ)
-                      for engine in categories[categ]
-                      if (engine.name, categ) not in disabled_engines)
+        result.extend(
+            EngineRef(engine.name, categ)
+            for engine in categories[categ]
+            if (engine.name, categ) not in disabled_engines
+        )
     return result
 
 
@@ -170,8 +173,11 @@ def parse_generic(preferences: Preferences, form: Dict[str, str], disabled_engin
         # parse the form only if the categories are not locked
         for pd_name, pd in form.items():
             if pd_name == 'engines':
-                pd_engines = [EngineRef(engine_name, engines[engine_name].categories[0])
-                              for engine_name in map(str.strip, pd.split(',')) if engine_name in engines]
+                pd_engines = [
+                    EngineRef(engine_name, engines[engine_name].categories[0])
+                    for engine_name in map(str.strip, pd.split(','))
+                    if engine_name in engines
+                ]
                 if pd_engines:
                     query_engineref_list.extend(pd_engines)
                     explicit_engine_list = True
@@ -206,8 +212,9 @@ def parse_engine_data(form):
     return engine_data
 
 
-def get_search_query_from_webapp(preferences: Preferences, form: Dict[str, str])\
-        -> Tuple[SearchQuery, RawTextQuery, List[EngineRef], List[EngineRef]]:
+def get_search_query_from_webapp(
+    preferences: Preferences, form: Dict[str, str]
+) -> Tuple[SearchQuery, RawTextQuery, List[EngineRef], List[EngineRef]]:
     # no text for the query ?
     if not form.get('q'):
         raise SearxParameterException('q', '')
@@ -239,12 +246,23 @@ def get_search_query_from_webapp(preferences: Preferences, form: Dict[str, str])
         query_engineref_list = parse_generic(preferences, form, disabled_engines)
 
     query_engineref_list = deduplicate_engineref_list(query_engineref_list)
-    query_engineref_list, query_engineref_list_unknown, query_engineref_list_notoken =\
-        validate_engineref_list(query_engineref_list, preferences)
-
-    return (SearchQuery(query, query_engineref_list, query_lang, query_safesearch, query_pageno,
-                        query_time_range, query_timeout, external_bang=external_bang,
-                        engine_data=engine_data),
-            raw_text_query,
-            query_engineref_list_unknown,
-            query_engineref_list_notoken)
+    query_engineref_list, query_engineref_list_unknown, query_engineref_list_notoken = validate_engineref_list(
+        query_engineref_list, preferences
+    )
+
+    return (
+        SearchQuery(
+            query,
+            query_engineref_list,
+            query_lang,
+            query_safesearch,
+            query_pageno,
+            query_time_range,
+            query_timeout,
+            external_bang=external_bang,
+            engine_data=engine_data,
+        ),
+        raw_text_query,
+        query_engineref_list_unknown,
+        query_engineref_list_notoken,
+    )
diff --git a/searx/webapp.py b/searx/webapp.py
index 7729eb538..a7812f181 100755
--- a/searx/webapp.py
+++ b/searx/webapp.py
@@ -146,11 +146,7 @@ STATS_SORT_PARAMETERS = {
 }
 
 # Flask app
-app = Flask(
-    __name__,
-    static_folder=settings['ui']['static_path'],
-    template_folder=templates_path
-)
+app = Flask(__name__, static_folder=settings['ui']['static_path'], template_folder=templates_path)
 
 app.jinja_env.trim_blocks = True
 app.jinja_env.lstrip_blocks = True
@@ -171,14 +167,10 @@ _category_names = (
     gettext('news'),
     gettext('map'),
     gettext('onions'),
-    gettext('science')
+    gettext('science'),
 )
 
-_simple_style = (
-    gettext('auto'),
-    gettext('light'),
-    gettext('dark')
-)
+_simple_style = (gettext('auto'), gettext('light'), gettext('dark'))
 
 #
 timeout_text = gettext('timeout')
@@ -214,11 +206,15 @@ exception_classname_to_text = {
 
 # monkey patch for flask_babel.get_translations
 _flask_babel_get_translations = flask_babel.get_translations
+
+
 def _get_translations():
     if has_request_context() and request.form.get('use-translation') == 'oc':
         babel_ext = flask_babel.current_app.extensions['babel']
         return Translations.load(next(babel_ext.translation_directories), 'oc')
     return _flask_babel_get_translations()
+
+
 flask_babel.get_translations = _get_translations
 
 
@@ -286,13 +282,10 @@ def code_highlighter(codelines, language=None):
             line_code_start = line
 
         # new codeblock is detected
-        if last_line is not None and\
-           last_line + 1 != line:
+        if last_line is not None and last_line + 1 != line:
 
             # highlight last codepart
-            formatter = HtmlFormatter(
-                linenos='inline', linenostart=line_code_start, cssclass="code-highlight"
-            )
+            formatter = HtmlFormatter(linenos='inline', linenostart=line_code_start, cssclass="code-highlight")
             html_code = html_code + highlight(tmp_code, lexer, formatter)
 
             # reset conditions for next codepart
@@ -355,16 +348,9 @@ def proxify(url):
     url_params = dict(mortyurl=url.encode())
 
     if settings['result_proxy'].get('key'):
-        url_params['mortyhash'] = hmac.new(
-            settings['result_proxy']['key'],
-            url.encode(),
-            hashlib.sha256
-        ).hexdigest()
-
-    return '{0}?{1}'.format(
-        settings['result_proxy']['url'],
-        urlencode(url_params)
-    )
+        url_params['mortyhash'] = hmac.new(settings['result_proxy']['key'], url.encode(), hashlib.sha256).hexdigest()
+
+    return '{0}?{1}'.format(settings['result_proxy']['url'], urlencode(url_params))
 
 
 def image_proxify(url):
@@ -377,10 +363,12 @@ def image_proxify(url):
 
     if url.startswith('data:image/'):
         # 50 is an arbitrary number to get only the beginning of the image.
-        partial_base64 = url[len('data:image/'):50].split(';')
-        if len(partial_base64) == 2 \
-           and partial_base64[0] in ['gif', 'png', 'jpeg', 'pjpeg', 'webp', 'tiff', 'bmp']\
-           and partial_base64[1].startswith('base64,'):
+        partial_base64 = url[len('data:image/') : 50].split(';')
+        if (
+            len(partial_base64) == 2
+            and partial_base64[0] in ['gif', 'png', 'jpeg', 'pjpeg', 'webp', 'tiff', 'bmp']
+            and partial_base64[1].startswith('base64,')
+        ):
             return url
         return None
 
@@ -389,8 +377,7 @@ def image_proxify(url):
 
     h = new_hmac(settings['server']['secret_key'], url.encode())
 
-    return '{0}?{1}'.format(url_for('image_proxy'),
-                            urlencode(dict(url=url.encode(), h=h)))
+    return '{0}?{1}'.format(url_for('image_proxy'), urlencode(dict(url=url.encode(), h=h)))
 
 
 def get_translations():
@@ -412,7 +399,8 @@ def _get_enable_categories(all_categories):
     disabled_engines = request.preferences.engines.get_disabled()
     enabled_categories = set(
         # pylint: disable=consider-using-dict-items
-        category for engine_name in engines
+        category
+        for engine_name in engines
         for category in engines[engine_name].categories
         if (engine_name, category) not in disabled_engines
     )
@@ -423,10 +411,7 @@ def get_pretty_url(parsed_url):
     path = parsed_url.path
     path = path[:-1] if len(path) > 0 and path[-1] == '/' else path
     path = path.replace("/", " › ")
-    return [
-        parsed_url.scheme + "://" + parsed_url.netloc,
-        path
-    ]
+    return [parsed_url.scheme + "://" + parsed_url.netloc, path]
 
 
 def render(template_name, override_theme=None, **kwargs):
@@ -448,7 +433,7 @@ def render(template_name, override_theme=None, **kwargs):
     kwargs['categories'] = _get_enable_categories(kwargs['all_categories'])
 
     # i18n
-    kwargs['language_codes'] = [ l for l in languages if l[0] in settings['search']['languages'] ]
+    kwargs['language_codes'] = [l for l in languages if l[0] in settings['search']['languages']]
     kwargs['translations'] = json.dumps(get_translations(), separators=(',', ':'))
 
     locale = request.preferences.get_value('locale')
@@ -458,12 +443,11 @@ def render(template_name, override_theme=None, **kwargs):
         kwargs['rtl'] = True
     if 'current_language' not in kwargs:
         kwargs['current_language'] = match_language(
-            request.preferences.get_value('language'), settings['search']['languages'] )
+            request.preferences.get_value('language'), settings['search']['languages']
+        )
 
     # values from settings
-    kwargs['search_formats'] = [
-        x for x in settings['search']['formats'] if x != 'html'
-    ]
+    kwargs['search_formats'] = [x for x in settings['search']['formats'] if x != 'html']
     kwargs['instance_name'] = get_setting('general.instance_name')
     kwargs['searx_version'] = VERSION_STRING
     kwargs['searx_git_url'] = GIT_URL
@@ -477,9 +461,7 @@ def render(template_name, override_theme=None, **kwargs):
     kwargs['proxify_results'] = settings.get('result_proxy', {}).get('proxify_results', True)
     kwargs['get_result_template'] = get_result_template
     kwargs['opensearch_url'] = (
-        url_for('opensearch')
-        + '?'
-        + urlencode({'method': kwargs['method'], 'autocomplete': kwargs['autocomplete']})
+        url_for('opensearch') + '?' + urlencode({'method': kwargs['method'], 'autocomplete': kwargs['autocomplete']})
     )
 
     # scripts from plugins
@@ -495,8 +477,7 @@ def render(template_name, override_theme=None, **kwargs):
             kwargs['styles'].add(css)
 
     start_time = default_timer()
-    result = render_template(
-        '{}/{}'.format(kwargs['theme'], template_name), **kwargs)
+    result = render_template('{}/{}'.format(kwargs['theme'], template_name), **kwargs)
     request.render_time += default_timer() - start_time  # pylint: disable=assigning-non-slot
 
     return result
@@ -541,7 +522,7 @@ def pre_request():
     # language is defined neither in settings nor in preferences
     # use browser headers
     if not preferences.get_value("language"):
-        language =  _get_browser_language(request, settings['search']['languages'])
+        language = _get_browser_language(request, settings['search']['languages'])
         preferences.parse_dict({"language": language})
 
     # locale is defined neither in settings nor in preferences
@@ -555,8 +536,7 @@ def pre_request():
     allowed_plugins = preferences.plugins.get_enabled()
     disabled_plugins = preferences.plugins.get_disabled()
     for plugin in plugins:
-        if ((plugin.default_on and plugin.id not in disabled_plugins)
-                or plugin.id in allowed_plugins):
+        if (plugin.default_on and plugin.id not in disabled_plugins) or plugin.id in allowed_plugins:
             request.user_plugins.append(plugin)
 
 
@@ -573,17 +553,20 @@ def add_default_headers(response):
 @app.after_request
 def post_request(response):
     total_time = default_timer() - request.start_time
-    timings_all = ['total;dur=' + str(round(total_time * 1000, 3)),
-                   'render;dur=' + str(round(request.render_time * 1000, 3))]
+    timings_all = [
+        'total;dur=' + str(round(total_time * 1000, 3)),
+        'render;dur=' + str(round(request.render_time * 1000, 3)),
+    ]
     if len(request.timings) > 0:
         timings = sorted(request.timings, key=lambda v: v['total'])
         timings_total = [
-            'total_' + str(i) + '_' + v['engine'] +  ';dur=' + str(round(v['total'] * 1000, 3))
+            'total_' + str(i) + '_' + v['engine'] + ';dur=' + str(round(v['total'] * 1000, 3))
             for i, v in enumerate(timings)
         ]
         timings_load = [
             'load_' + str(i) + '_' + v['engine'] + ';dur=' + str(round(v['load'] * 1000, 3))
-            for i, v in enumerate(timings) if v.get('load')
+            for i, v in enumerate(timings)
+            if v.get('load')
         ]
         timings_all = timings_all + timings_total + timings_load
     response.headers.add('Server-Timing', ', '.join(timings_all))
@@ -592,10 +575,7 @@ def post_request(response):
 
 def index_error(output_format, error_message):
     if output_format == 'json':
-        return Response(
-            json.dumps({'error': error_message}),
-            mimetype='application/json'
-        )
+        return Response(json.dumps({'error': error_message}), mimetype='application/json')
     if output_format == 'csv':
         response = Response('', mimetype='application/csv')
         cont_disp = 'attachment;Filename=searx.csv'
@@ -678,9 +658,7 @@ def search():
     raw_text_query = None
     result_container = None
     try:
-        search_query, raw_text_query, _, _ = get_search_query_from_webapp(
-            request.preferences, request.form
-        )
+        search_query, raw_text_query, _, _ = get_search_query_from_webapp(request.preferences, request.form)
         # search = Search(search_query) #  without plugins
         search = SearchWithPlugins(search_query, request.user_plugins, request)  # pylint: disable=redefined-outer-name
 
@@ -736,10 +714,9 @@ def search():
                     if hours == 0:
                         result['publishedDate'] = gettext('{minutes} minute(s) ago').format(minutes=minutes)
                     else:
-                        result['publishedDate'] = gettext(
-                            '{hours} hour(s), {minutes} minute(s) ago').format(
-                                hours=hours, minutes=minutes
-                            )
+                        result['publishedDate'] = gettext('{hours} hour(s), {minutes} minute(s) ago').format(
+                            hours=hours, minutes=minutes
+                        )
                 else:
                     result['publishedDate'] = format_date(result['publishedDate'])
 
@@ -752,11 +729,9 @@ def search():
             'corrections': list(result_container.corrections),
             'infoboxes': result_container.infoboxes,
             'suggestions': list(result_container.suggestions),
-            'unresponsive_engines': __get_translated_errors(result_container.unresponsive_engines)
+            'unresponsive_engines': __get_translated_errors(result_container.unresponsive_engines),
         }
-        response = json.dumps(
-            x,  default = lambda item: list(item) if isinstance(item, set) else item
-        )
+        response = json.dumps(x, default=lambda item: list(item) if isinstance(item, set) else item)
         return Response(response, mimetype='application/json')
 
     if output_format == 'csv':
@@ -800,21 +775,17 @@ def search():
     # suggestions: use RawTextQuery to get the suggestion URLs with the same bang
     suggestion_urls = list(
         map(
-            lambda suggestion: {
-                'url': raw_text_query.changeQuery(suggestion).getFullQuery(),
-                'title': suggestion
-            },
-            result_container.suggestions
-        ))
+            lambda suggestion: {'url': raw_text_query.changeQuery(suggestion).getFullQuery(), 'title': suggestion},
+            result_container.suggestions,
+        )
+    )
 
     correction_urls = list(
         map(
-            lambda correction: {
-                'url': raw_text_query.changeQuery(correction).getFullQuery(),
-                'title': correction
-            },
-            result_container.corrections
-        ))
+            lambda correction: {'url': raw_text_query.changeQuery(correction).getFullQuery(), 'title': correction},
+            result_container.corrections,
+        )
+    )
 
     return render(
         # fmt: off
@@ -899,9 +870,7 @@ def autocompleter():
             language = language.split('-')[0]
 
         # run autocompletion
-        raw_results = search_autocomplete(
-            request.preferences.get_value('autocomplete'), sug_prefix, language
-        )
+        raw_results = search_autocomplete(request.preferences.get_value('autocomplete'), sug_prefix, language)
         for result in raw_results:
             # attention: this loop will change raw_text_query object and this is
             # the reason why the sug_prefix was stored before (see above)
@@ -952,16 +921,11 @@ def preferences():
     allowed_plugins = request.preferences.plugins.get_enabled()
 
     # stats for preferences page
-    filtered_engines = dict(
-        filter(
-            lambda kv: (kv[0], request.preferences.validate_token(kv[1])),
-            engines.items()
-        )
-    )
+    filtered_engines = dict(filter(lambda kv: (kv[0], request.preferences.validate_token(kv[1])), engines.items()))
 
     engines_by_category = {}
 
-    for c in categories: # pylint: disable=consider-using-dict-items
+    for c in categories:  # pylint: disable=consider-using-dict-items
         engines_by_category[c] = [e for e in categories[c] if e.name in filtered_engines]
         # sort the engines alphabetically since the order in settings.yml is meaningless.
         list.sort(engines_by_category[c], key=lambda e: e.name)
@@ -996,8 +960,9 @@ def preferences():
     reliabilities = {}
     engine_errors = get_engine_errors(filtered_engines)
     checker_results = checker_get_result()
-    checker_results = checker_results['engines'] \
-        if checker_results['status'] == 'ok' and 'engines' in checker_results else {}
+    checker_results = (
+        checker_results['engines'] if checker_results['status'] == 'ok' and 'engines' in checker_results else {}
+    )
     for _, e in filtered_engines.items():
         checker_result = checker_results.get(e.name, {})
         checker_success = checker_result.get('success', True)
@@ -1089,10 +1054,7 @@ def _is_selected_language_supported(engine, preferences):  # pylint: disable=red
     if language == 'all':
         return True
     x = match_language(
-        language,
-        getattr(engine, 'supported_languages', []),
-        getattr(engine, 'language_aliases', {}),
-        None
+        language, getattr(engine, 'supported_languages', []), getattr(engine, 'language_aliases', {}), None
     )
     return bool(x)
 
@@ -1121,15 +1083,9 @@ def image_proxy():
             'DNT': '1',
         }
         set_context_network_name('image_proxy')
-        resp, stream = http_stream(
-            method = 'GET',
-            url = url,
-            headers = request_headers
-        )
+        resp, stream = http_stream(method='GET', url=url, headers=request_headers)
         content_length = resp.headers.get('Content-Length')
-        if (content_length
-            and content_length.isdigit()
-            and int(content_length) > maximum_size ):
+        if content_length and content_length.isdigit() and int(content_length) > maximum_size:
             return 'Max size', 400
 
         if resp.status_code != 200:
@@ -1165,15 +1121,8 @@ def image_proxy():
             logger.debug('Exception while closing response', e)
 
     try:
-        headers = dict_subset(
-            resp.headers,
-            {'Content-Type', 'Content-Encoding', 'Content-Length', 'Length'}
-        )
-        response = Response(
-            stream,
-            mimetype=resp.headers['Content-Type'],
-            headers=headers,
-            direct_passthrough=True)
+        headers = dict_subset(resp.headers, {'Content-Type', 'Content-Encoding', 'Content-Length', 'Length'})
+        response = Response(stream, mimetype=resp.headers['Content-Type'], headers=headers, direct_passthrough=True)
         response.call_on_close(close_stream)
         return response
     except httpx.HTTPError:
@@ -1189,11 +1138,11 @@ def engine_descriptions():
         for engine, description in ENGINE_DESCRIPTIONS.get(locale, {}).items():
             result[engine] = description
     for engine, description in result.items():
-        if len(description) ==2 and description[1] == 'ref':
+        if len(description) == 2 and description[1] == 'ref':
             ref_engine, ref_lang = description[0].split(':')
             description = ENGINE_DESCRIPTIONS[ref_lang][ref_engine]
         if isinstance(description, str):
-            description = [ description, 'wikipedia' ]
+            description = [description, 'wikipedia']
         result[engine] = description
     return jsonify(result)
 
@@ -1204,11 +1153,7 @@ def stats():
     sort_order = request.args.get('sort', default='name', type=str)
     selected_engine_name = request.args.get('engine', default=None, type=str)
 
-    filtered_engines = dict(
-        filter(
-            lambda kv: (kv[0], request.preferences.validate_token(kv[1])),
-            engines.items()
-        ))
+    filtered_engines = dict(filter(lambda kv: (kv[0], request.preferences.validate_token(kv[1])), engines.items()))
     if selected_engine_name:
         if selected_engine_name not in filtered_engines:
             selected_engine_name = None
@@ -1217,8 +1162,7 @@ def stats():
 
     checker_results = checker_get_result()
     checker_results = (
-        checker_results['engines']
-        if checker_results['status'] == 'ok' and 'engines' in checker_results else {}
+        checker_results['engines'] if checker_results['status'] == 'ok' and 'engines' in checker_results else {}
     )
 
     engine_stats = get_engines_stats(filtered_engines)
@@ -1256,11 +1200,7 @@ def stats():
 
 @app.route('/stats/errors', methods=['GET'])
 def stats_errors():
-    filtered_engines = dict(
-        filter(
-            lambda kv: (kv[0], request.preferences.validate_token(kv[1])),
-            engines.items()
-        ))
+    filtered_engines = dict(filter(lambda kv: (kv[0], request.preferences.validate_token(kv[1])), engines.items()))
     result = get_engine_errors(filtered_engines)
     return jsonify(result)
 
@@ -1273,13 +1213,16 @@ def stats_checker():
 
 @app.route('/robots.txt', methods=['GET'])
 def robots():
-    return Response("""User-agent: *
+    return Response(
+        """User-agent: *
 Allow: /
 Allow: /about
 Disallow: /stats
 Disallow: /preferences
 Disallow: /*?*q=*
-""", mimetype='text/plain')
+""",
+        mimetype='text/plain',
+    )
 
 
 @app.route('/opensearch.xml', methods=['GET'])
@@ -1293,34 +1236,21 @@ def opensearch():
     if request.headers.get('User-Agent', '').lower().find('webkit') >= 0:
         method = 'get'
 
-    ret = render(
-        'opensearch.xml',
-        opensearch_method=method,
-        override_theme='__common__'
-    )
+    ret = render('opensearch.xml', opensearch_method=method, override_theme='__common__')
 
-    resp = Response(
-        response = ret,
-        status = 200,
-        mimetype = "application/opensearchdescription+xml"
-    )
+    resp = Response(response=ret, status=200, mimetype="application/opensearchdescription+xml")
     return resp
 
 
 @app.route('/favicon.ico')
 def favicon():
     return send_from_directory(
-        os.path.join(
-            app.root_path,
-            settings['ui']['static_path'],
-            'themes',
-            get_current_theme_name(),
-            'img'
-        ),
+        os.path.join(app.root_path, settings['ui']['static_path'], 'themes', get_current_theme_name(), 'img'),
         'favicon.png',
-        mimetype = 'image/vnd.microsoft.icon'
+        mimetype='image/vnd.microsoft.icon',
     )
 
+
 @app.route('/clear_cookies')
 def clear_cookies():
     resp = make_response(redirect(url_for('index', _external=True)))
@@ -1341,43 +1271,47 @@ def config():
         if isinstance(engine.supported_languages, dict):
             supported_languages = list(engine.supported_languages.keys())
 
-        _engines.append({
-            'name': name,
-            'categories': engine.categories,
-            'shortcut': engine.shortcut,
-            'enabled': not engine.disabled,
-            'paging': engine.paging,
-            'language_support': engine.language_support,
-            'supported_languages': supported_languages,
-            'safesearch': engine.safesearch,
-            'time_range_support': engine.time_range_support,
-            'timeout': engine.timeout
-        })
+        _engines.append(
+            {
+                'name': name,
+                'categories': engine.categories,
+                'shortcut': engine.shortcut,
+                'enabled': not engine.disabled,
+                'paging': engine.paging,
+                'language_support': engine.language_support,
+                'supported_languages': supported_languages,
+                'safesearch': engine.safesearch,
+                'time_range_support': engine.time_range_support,
+                'timeout': engine.timeout,
+            }
+        )
 
     _plugins = []
     for _ in plugins:
         _plugins.append({'name': _.name, 'enabled': _.default_on})
 
-    return jsonify({
-        'categories': list(categories.keys()),
-        'engines': _engines,
-        'plugins': _plugins,
-        'instance_name': settings['general']['instance_name'],
-        'locales': LOCALE_NAMES,
-        'default_locale': settings['ui']['default_locale'],
-        'autocomplete': settings['search']['autocomplete'],
-        'safe_search': settings['search']['safe_search'],
-        'default_theme': settings['ui']['default_theme'],
-        'version': VERSION_STRING,
-        'brand': {
-            'CONTACT_URL': get_setting('general.contact_url'),
-            'GIT_URL': GIT_URL,
-            'GIT_BRANCH': GIT_BRANCH,
-            'DOCS_URL': get_setting('brand.docs_url'),
-        },
-        'doi_resolvers': list(settings['doi_resolvers'].keys()),
-        'default_doi_resolver': settings['default_doi_resolver'],
-    })
+    return jsonify(
+        {
+            'categories': list(categories.keys()),
+            'engines': _engines,
+            'plugins': _plugins,
+            'instance_name': settings['general']['instance_name'],
+            'locales': LOCALE_NAMES,
+            'default_locale': settings['ui']['default_locale'],
+            'autocomplete': settings['search']['autocomplete'],
+            'safe_search': settings['search']['safe_search'],
+            'default_theme': settings['ui']['default_theme'],
+            'version': VERSION_STRING,
+            'brand': {
+                'CONTACT_URL': get_setting('general.contact_url'),
+                'GIT_URL': GIT_URL,
+                'GIT_BRANCH': GIT_BRANCH,
+                'DOCS_URL': get_setting('brand.docs_url'),
+            },
+            'doi_resolvers': list(settings['doi_resolvers'].keys()),
+            'default_doi_resolver': settings['default_doi_resolver'],
+        }
+    )
 
 
 @app.errorhandler(404)
@@ -1388,9 +1322,7 @@ def page_not_found(_e):
 # see https://flask.palletsprojects.com/en/1.1.x/cli/
 # True if "FLASK_APP=searx/webapp.py FLASK_ENV=development flask run"
 flask_run_development = (
-    os.environ.get("FLASK_APP") is not None
-    and os.environ.get("FLASK_ENV") == 'development'
-    and is_flask_run_cmdline()
+    os.environ.get("FLASK_APP") is not None and os.environ.get("FLASK_ENV") == 'development' and is_flask_run_cmdline()
 )
 
 # True if reload feature is activated of werkzeug, False otherwise (including uwsgi, etc..)
@@ -1399,30 +1331,23 @@ flask_run_development = (
 werkzeug_reloader = flask_run_development or (searx_debug and __name__ == "__main__")
 
 # initialize the engines except on the first run of the werkzeug server.
-if (not werkzeug_reloader
-    or (werkzeug_reloader
-        and os.environ.get("WERKZEUG_RUN_MAIN") == "true") ):
+if not werkzeug_reloader or (werkzeug_reloader and os.environ.get("WERKZEUG_RUN_MAIN") == "true"):
     plugin_initialize(app)
     search_initialize(enable_checker=True, check_network=True)
 
 
 def run():
-    logger.debug(
-        'starting webserver on %s:%s',
-        settings['server']['bind_address'],
-        settings['server']['port']
-    )
+    logger.debug('starting webserver on %s:%s', settings['server']['bind_address'], settings['server']['port'])
     app.run(
-        debug = searx_debug,
-        use_debugger = searx_debug,
-        port = settings['server']['port'],
-        host = settings['server']['bind_address'],
-        threaded = True,
-        extra_files = [
-            get_default_settings_path()
-        ],
+        debug=searx_debug,
+        use_debugger=searx_debug,
+        port=settings['server']['port'],
+        host=settings['server']['bind_address'],
+        threaded=True,
+        extra_files=[get_default_settings_path()],
     )
 
+
 application = app
 patch_application(app)
 
diff --git a/searx/webutils.py b/searx/webutils.py
index c27324908..737e5a82f 100644
--- a/searx/webutils.py
+++ b/searx/webutils.py
@@ -106,8 +106,7 @@ def highlight_content(content, query):
 
     if content.lower().find(query.lower()) > -1:
         query_regex = '({0})'.format(re.escape(query))
-        content = re.sub(query_regex, '<span class="highlight">\\1</span>',
-                         content, flags=re.I | re.U)
+        content = re.sub(query_regex, '<span class="highlight">\\1</span>', content, flags=re.I | re.U)
     else:
         regex_parts = []
         for chunk in query.split():
@@ -119,8 +118,7 @@ def highlight_content(content, query):
             else:
                 regex_parts.append('{0}'.format(re.escape(chunk)))
         query_regex = '({0})'.format('|'.join(regex_parts))
-        content = re.sub(query_regex, '<span class="highlight">\\1</span>',
-                         content, flags=re.I | re.U)
+        content = re.sub(query_regex, '<span class="highlight">\\1</span>', content, flags=re.I | re.U)
 
     return content
 
diff --git a/searxng_extra/standalone_searx.py b/searxng_extra/standalone_searx.py
index de8a0d77f..9ac8c8af2 100755
--- a/searxng_extra/standalone_searx.py
+++ b/searxng_extra/standalone_searx.py
@@ -62,7 +62,7 @@ Example to run it from python:
     },
     "suggestions": [...]
 }
-""" # pylint: disable=line-too-long
+"""  # pylint: disable=line-too-long
 
 import argparse
 import sys
@@ -80,7 +80,7 @@ EngineCategoriesVar = Optional[List[str]]
 
 
 def get_search_query(
-        args: argparse.Namespace, engine_categories: EngineCategoriesVar = None
+    args: argparse.Namespace, engine_categories: EngineCategoriesVar = None
 ) -> searx.search.SearchQuery:
     """Get  search results for the query"""
     if engine_categories is None:
@@ -94,14 +94,12 @@ def get_search_query(
         "categories": category,
         "pageno": str(args.pageno),
         "language": args.lang,
-        "time_range": args.timerange
+        "time_range": args.timerange,
     }
-    preferences = searx.preferences.Preferences(
-        ['oscar'], engine_categories, searx.engines.engines, [])
+    preferences = searx.preferences.Preferences(['oscar'], engine_categories, searx.engines.engines, [])
     preferences.key_value_settings['safesearch'].parse(args.safesearch)
 
-    search_query = searx.webadapter.get_search_query_from_webapp(
-        preferences, form)[0]
+    search_query = searx.webadapter.get_search_query_from_webapp(preferences, form)[0]
     return search_query
 
 
@@ -143,14 +141,13 @@ def to_dict(search_query: searx.search.SearchQuery) -> Dict[str, Any]:
         "suggestions": list(result_container.suggestions),
         "answers": list(result_container.answers),
         "paging": result_container.paging,
-        "results_number": result_container.results_number()
+        "results_number": result_container.results_number(),
     }
     return result_container_json
 
 
 def parse_argument(
-        args: Optional[List[str]]=None,
-        category_choices: EngineCategoriesVar=None
+    args: Optional[List[str]] = None, category_choices: EngineCategoriesVar = None
 ) -> argparse.Namespace:
     """Parse command line.
 
@@ -174,24 +171,23 @@ def parse_argument(
     if not category_choices:
         category_choices = list(searx.engines.categories.keys())
     parser = argparse.ArgumentParser(description='Standalone searx.')
-    parser.add_argument('query', type=str,
-                        help='Text query')
-    parser.add_argument('--category', type=str, nargs='?',
-                        choices=category_choices,
-                        default='general',
-                        help='Search category')
-    parser.add_argument('--lang', type=str, nargs='?', default='all',
-                        help='Search language')
-    parser.add_argument('--pageno', type=int, nargs='?', default=1,
-                        help='Page number starting from 1')
+    parser.add_argument('query', type=str, help='Text query')
     parser.add_argument(
-        '--safesearch', type=str, nargs='?',
-        choices=['0', '1', '2'], default='0',
-        help='Safe content filter from none to strict')
+        '--category', type=str, nargs='?', choices=category_choices, default='general', help='Search category'
+    )
+    parser.add_argument('--lang', type=str, nargs='?', default='all', help='Search language')
+    parser.add_argument('--pageno', type=int, nargs='?', default=1, help='Page number starting from 1')
     parser.add_argument(
-        '--timerange', type=str,
-        nargs='?', choices=['day', 'week', 'month', 'year'],
-        help='Filter by time range')
+        '--safesearch',
+        type=str,
+        nargs='?',
+        choices=['0', '1', '2'],
+        default='0',
+        help='Safe content filter from none to strict',
+    )
+    parser.add_argument(
+        '--timerange', type=str, nargs='?', choices=['day', 'week', 'month', 'year'], help='Filter by time range'
+    )
     return parser.parse_args(args)
 
 
@@ -206,6 +202,4 @@ if __name__ == '__main__':
     searx.search.initialize_processors(settings_engines)
     search_q = get_search_query(prog_args, engine_categories=engine_cs)
     res_dict = to_dict(search_q)
-    sys.stdout.write(dumps(
-        res_dict, sort_keys=True, indent=4, ensure_ascii=False,
-        default=json_serial))
+    sys.stdout.write(dumps(res_dict, sort_keys=True, indent=4, ensure_ascii=False, default=json_serial))
diff --git a/searxng_extra/update/update_currencies.py b/searxng_extra/update/update_currencies.py
index 93ac15aa5..3373e2455 100755
--- a/searxng_extra/update/update_currencies.py
+++ b/searxng_extra/update/update_currencies.py
@@ -85,9 +85,7 @@ def add_currency_label(db, label, iso4217, language):
 
 
 def wikidata_request_result_iterator(request):
-    result = wikidata.send_wikidata_query(
-        request.replace('%LANGUAGES_SPARQL%', LANGUAGES_SPARQL)
-    )
+    result = wikidata.send_wikidata_query(request.replace('%LANGUAGES_SPARQL%', LANGUAGES_SPARQL))
     if result is not None:
         for r in result['results']['bindings']:
             yield r
@@ -151,5 +149,6 @@ def main():
     with open(get_filename(), 'w', encoding='utf8') as f:
         json.dump(db, f, ensure_ascii=False, indent=4)
 
+
 if __name__ == '__main__':
     main()
diff --git a/searxng_extra/update/update_engine_descriptions.py b/searxng_extra/update/update_engine_descriptions.py
index 2e16e1029..51cfc7cc2 100755
--- a/searxng_extra/update/update_engine_descriptions.py
+++ b/searxng_extra/update/update_engine_descriptions.py
@@ -56,7 +56,8 @@ NOT_A_DESCRIPTION = [
 
 SKIP_ENGINE_SOURCE = [
     # fmt: off
-    ('gitlab', 'wikidata')  # descriptions are about wikipedia disambiguation pages
+    ('gitlab', 'wikidata')
+    # descriptions are about wikipedia disambiguation pages
     # fmt: on
 ]
 
@@ -94,10 +95,7 @@ def update_description(engine_name, lang, description, source, replace=True):
 
 
 def get_wikipedia_summary(lang, pageid):
-    params = {
-        'language': lang.replace('_','-'),
-        'headers': {}
-    }
+    params = {'language': lang.replace('_', '-'), 'headers': {}}
     searx.engines.engines['wikipedia'].request(pageid, params)
     try:
         response = searx.network.get(params['url'], headers=params['headers'], timeout=10)
@@ -162,10 +160,7 @@ def initialize():
     global IDS, WIKIPEDIA_LANGUAGES, LANGUAGES_SPARQL
     searx.search.initialize()
     wikipedia_engine = searx.engines.engines['wikipedia']
-    WIKIPEDIA_LANGUAGES = {
-        language: wikipedia_engine.url_lang(language.replace('_', '-'))
-        for language in LANGUAGES
-    }
+    WIKIPEDIA_LANGUAGES = {language: wikipedia_engine.url_lang(language.replace('_', '-')) for language in LANGUAGES}
     WIKIPEDIA_LANGUAGES['nb_NO'] = 'no'
     LANGUAGES_SPARQL = ', '.join(f"'{l}'" for l in set(WIKIPEDIA_LANGUAGES.values()))
     for engine_name, engine in searx.engines.engines.items():
@@ -180,9 +175,7 @@ def initialize():
 def fetch_wikidata_descriptions():
     searx.network.set_timeout_for_thread(60)
     result = wikidata.send_wikidata_query(
-        SPARQL_DESCRIPTION
-        .replace('%IDS%', IDS)
-        .replace('%LANGUAGES_SPARQL%', LANGUAGES_SPARQL)
+        SPARQL_DESCRIPTION.replace('%IDS%', IDS).replace('%LANGUAGES_SPARQL%', LANGUAGES_SPARQL)
     )
     if result is not None:
         for binding in result['results']['bindings']:
@@ -197,9 +190,7 @@ def fetch_wikidata_descriptions():
 
 def fetch_wikipedia_descriptions():
     result = wikidata.send_wikidata_query(
-        SPARQL_WIKIPEDIA_ARTICLE
-        .replace('%IDS%', IDS)
-        .replace('%LANGUAGES_SPARQL%', LANGUAGES_SPARQL)
+        SPARQL_WIKIPEDIA_ARTICLE.replace('%IDS%', IDS).replace('%LANGUAGES_SPARQL%', LANGUAGES_SPARQL)
     )
     if result is not None:
         for binding in result['results']['bindings']:
@@ -226,9 +217,9 @@ def fetch_website_description(engine_name, website):
         # the front page can't be fetched: skip this engine
         return
 
-    wikipedia_languages_r = { V: K for K, V in WIKIPEDIA_LANGUAGES.items() }
+    wikipedia_languages_r = {V: K for K, V in WIKIPEDIA_LANGUAGES.items()}
     languages = ['en', 'es', 'pt', 'ru', 'tr', 'fr']
-    languages = languages + [ l for l in LANGUAGES if l not in languages]
+    languages = languages + [l for l in LANGUAGES if l not in languages]
 
     previous_matched_lang = None
     previous_count = 0
@@ -281,9 +272,7 @@ def get_output():
        * description (if source = "wikipedia")
        * [f"engine:lang", "ref"] (reference to another existing description)
     """
-    output = {
-        locale: {} for locale in LOCALE_NAMES
-    }
+    output = {locale: {} for locale in LOCALE_NAMES}
 
     seen_descriptions = {}
 
diff --git a/searxng_extra/update/update_external_bangs.py b/searxng_extra/update/update_external_bangs.py
index 27882bb24..d5c6b585a 100755
--- a/searxng_extra/update/update_external_bangs.py
+++ b/searxng_extra/update/update_external_bangs.py
@@ -113,13 +113,13 @@ def parse_ddg_bangs(ddg_bangs):
 
         # only for the https protocol: "https://example.com" becomes "//example.com"
         if bang_url.startswith(HTTPS_COLON + '//'):
-            bang_url = bang_url[len(HTTPS_COLON):]
+            bang_url = bang_url[len(HTTPS_COLON) :]
 
         #
-        if bang_url.startswith(HTTP_COLON + '//') and bang_url[len(HTTP_COLON):] in bang_urls:
+        if bang_url.startswith(HTTP_COLON + '//') and bang_url[len(HTTP_COLON) :] in bang_urls:
             # if the bang_url uses the http:// protocol, and the same URL exists in https://
             # then reuse the https:// bang definition. (written //example.com)
-            bang_def_output = bang_urls[bang_url[len(HTTP_COLON):]]
+            bang_def_output = bang_urls[bang_url[len(HTTP_COLON) :]]
         else:
             # normal use case : new http:// URL or https:// URL (without "https:", see above)
             bang_rank = str(bang_definition['r'])
@@ -151,9 +151,6 @@ def get_bangs_filename():
 if __name__ == '__main__':
     bangs_url, bangs_version = get_bang_url()
     print(f'fetch bangs from {bangs_url}')
-    output = {
-        'version': bangs_version,
-        'trie': parse_ddg_bangs(fetch_ddg_bangs(bangs_url))
-    }
+    output = {'version': bangs_version, 'trie': parse_ddg_bangs(fetch_ddg_bangs(bangs_url))}
     with open(get_bangs_filename(), 'w', encoding="utf8") as fp:
         json.dump(output, fp, ensure_ascii=False, indent=4)
diff --git a/searxng_extra/update/update_firefox_version.py b/searxng_extra/update/update_firefox_version.py
index 3b536f296..750e955fd 100755
--- a/searxng_extra/update/update_firefox_version.py
+++ b/searxng_extra/update/update_firefox_version.py
@@ -40,7 +40,7 @@ def fetch_firefox_versions():
             url = urlparse(urljoin(URL, link))
             path = url.path
             if path.startswith(RELEASE_PATH):
-                version = path[len(RELEASE_PATH):-1]
+                version = path[len(RELEASE_PATH) : -1]
                 if NORMAL_REGEX.match(version):
                     versions.append(LooseVersion(version))
 
diff --git a/searxng_extra/update/update_languages.py b/searxng_extra/update/update_languages.py
index 2d7ffc104..526469342 100755
--- a/searxng_extra/update/update_languages.py
+++ b/searxng_extra/update/update_languages.py
@@ -31,8 +31,7 @@ def fetch_supported_languages():
     for engine_name in names:
         if hasattr(engines[engine_name], 'fetch_supported_languages'):
             engines_languages[engine_name] = engines[engine_name].fetch_supported_languages()
-            print("fetched %s languages from engine %s" % (
-                len(engines_languages[engine_name]), engine_name))
+            print("fetched %s languages from engine %s" % (len(engines_languages[engine_name]), engine_name))
             if type(engines_languages[engine_name]) == list:
                 engines_languages[engine_name] = sorted(engines_languages[engine_name])
 
@@ -60,8 +59,9 @@ def join_language_lists(engines_languages):
 
             # apply custom fixes if necessary
             if lang_code in getattr(engines[engine_name], 'language_aliases', {}).values():
-                lang_code = next(lc for lc, alias in engines[engine_name].language_aliases.items()
-                                 if lang_code == alias)
+                lang_code = next(
+                    lc for lc, alias in engines[engine_name].language_aliases.items() if lang_code == alias
+                )
 
             locale = get_locale(lang_code)
 
@@ -85,10 +85,12 @@ def join_language_lists(engines_languages):
                     english_name = None
 
                 # add language to list
-                language_list[short_code] = {'name': language_name,
-                                             'english_name': english_name,
-                                             'counter': set(),
-                                             'countries': dict()}
+                language_list[short_code] = {
+                    'name': language_name,
+                    'english_name': english_name,
+                    'counter': set(),
+                    'countries': dict(),
+                }
 
             # add language with country if not in list
             if lang_code != short_code and lang_code not in language_list[short_code]['countries']:
@@ -97,8 +99,7 @@ def join_language_lists(engines_languages):
                     # get country name from babel's Locale object
                     country_name = locale.get_territory_name()
 
-                language_list[short_code]['countries'][lang_code] = {'country_name': country_name,
-                                                                     'counter': set()}
+                language_list[short_code]['countries'][lang_code] = {'country_name': country_name, 'counter': set()}
 
             # count engine for both language_country combination and language alone
             language_list[short_code]['counter'].add(engine_name)
@@ -112,17 +113,23 @@ def join_language_lists(engines_languages):
 def filter_language_list(all_languages):
     min_engines_per_lang = 13
     min_engines_per_country = 7
-    main_engines = [engine_name for engine_name in engines.keys()
-                    if 'general' in engines[engine_name].categories and
-                       engines[engine_name].supported_languages and
-                       not engines[engine_name].disabled]
+    main_engines = [
+        engine_name
+        for engine_name in engines.keys()
+        if 'general' in engines[engine_name].categories
+        and engines[engine_name].supported_languages
+        and not engines[engine_name].disabled
+    ]
 
     # filter list to include only languages supported by most engines or all default general engines
-    filtered_languages = {code: lang for code, lang
-                          in all_languages.items()
-                          if (len(lang['counter']) >= min_engines_per_lang or
-                              all(main_engine in lang['counter']
-                                  for main_engine in main_engines))}
+    filtered_languages = {
+        code: lang
+        for code, lang in all_languages.items()
+        if (
+            len(lang['counter']) >= min_engines_per_lang
+            or all(main_engine in lang['counter'] for main_engine in main_engines)
+        )
+    }
 
     def _copy_lang_data(lang, country_name=None):
         new_dict = dict()
@@ -176,22 +183,24 @@ def write_languages_file(languages):
         "# -*- coding: utf-8 -*-",
         "# list of language codes",
         "# this file is generated automatically by utils/fetch_languages.py",
-        "language_codes ="
+        "language_codes =",
     )
 
-    language_codes = tuple([
-        (
-            code,
-            languages[code]['name'].split(' (')[0],
-            languages[code].get('country_name') or '',
-            languages[code].get('english_name') or ''
-        ) for code in sorted(languages)
-    ])
+    language_codes = tuple(
+        [
+            (
+                code,
+                languages[code]['name'].split(' (')[0],
+                languages[code].get('country_name') or '',
+                languages[code].get('english_name') or '',
+            )
+            for code in sorted(languages)
+        ]
+    )
 
     with open(languages_file, 'w') as new_file:
         file_content = "{file_headers} \\\n{language_codes}".format(
-            file_headers='\n'.join(file_headers),
-            language_codes=pformat(language_codes, indent=4)
+            file_headers='\n'.join(file_headers), language_codes=pformat(language_codes, indent=4)
         )
         new_file.write(file_content)
         new_file.close()
diff --git a/searxng_extra/update/update_osm_keys_tags.py b/searxng_extra/update/update_osm_keys_tags.py
index 77c715ba7..2916cbff1 100755
--- a/searxng_extra/update/update_osm_keys_tags.py
+++ b/searxng_extra/update/update_osm_keys_tags.py
@@ -84,9 +84,8 @@ PRESET_KEYS = {
     ('internet_access', 'ssid'): {'en': 'Wi-Fi'},
 }
 
-INCLUDED_KEYS = {
-    ('addr', )
-}
+INCLUDED_KEYS = {('addr',)}
+
 
 def get_preset_keys():
     results = collections.OrderedDict()
@@ -97,6 +96,7 @@ def get_preset_keys():
         r.setdefault('*', value)
     return results
 
+
 def get_keys():
     results = get_preset_keys()
     response = wikidata.send_wikidata_query(SPARQL_KEYS_REQUEST)
@@ -110,18 +110,16 @@ def get_keys():
             # label for the key "contact.email" is "Email"
             # whatever the language
             r = results.setdefault('contact', {})
-            r[keys[1]] = {
-                '*': {
-                    'en': keys[1]
-                }
-            }
+            r[keys[1]] = {'*': {'en': keys[1]}}
             continue
         if tuple(keys) in PRESET_KEYS:
             # skip presets (already set above)
             continue
-        if get_key_rank(':'.join(keys)) is None\
-            and ':'.join(keys) not in VALUE_TO_LINK\
-            and tuple(keys) not in INCLUDED_KEYS:
+        if (
+            get_key_rank(':'.join(keys)) is None
+            and ':'.join(keys) not in VALUE_TO_LINK
+            and tuple(keys) not in INCLUDED_KEYS
+        ):
             # keep only keys that will be displayed by openstreetmap.py
             continue
         label = key['itemLabel']['value'].lower()
@@ -160,6 +158,7 @@ def get_tags():
             results.setdefault(tag_category, {}).setdefault(tag_type, {}).setdefault(lang, label)
     return results
 
+
 def optimize_data_lang(translations):
     language_to_delete = []
     # remove "zh-hk" entry if the value is the same as "zh"
@@ -184,12 +183,14 @@ def optimize_data_lang(translations):
     for language in language_to_delete:
         del translations[language]
 
+
 def optimize_tags(data):
     for v in data.values():
         for translations in v.values():
             optimize_data_lang(translations)
     return data
 
+
 def optimize_keys(data):
     for k, v in data.items():
         if k == '*':
@@ -198,9 +199,11 @@ def optimize_keys(data):
             optimize_keys(v)
     return data
 
+
 def get_osm_tags_filename():
     return Path(searx_dir) / "data" / "osm_keys_tags.json"
 
+
 if __name__ == '__main__':
 
     set_timeout_for_thread(60)
diff --git a/searxng_extra/update/update_pygments.py b/searxng_extra/update/update_pygments.py
index fee63faa5..68aaad0f7 100755
--- a/searxng_extra/update/update_pygments.py
+++ b/searxng_extra/update/update_pygments.py
@@ -120,7 +120,7 @@ def get_css(cssclass, style):
     css_text = HtmlFormatter(style=style).get_style_defs(cssclass)
     result += cssclass + RULE_CODE_LINENOS + '\n\n'
     for line in css_text.splitlines():
-        if ' ' in line  and not line.startswith(cssclass):
+        if ' ' in line and not line.startswith(cssclass):
             line = cssclass + ' ' + line
         result += line + '\n'
     return result
diff --git a/tests/__init__.py b/tests/__init__.py
index c823cec87..8399f0604 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -50,5 +50,6 @@ class SearxTestCase(aiounittest.AsyncTestCase):
 
         def cleanup_patch():
             setattr(obj, attr, previous_value)
+
         self.addCleanup(cleanup_patch)
         setattr(obj, attr, value)
diff --git a/tests/robot/__main__.py b/tests/robot/__main__.py
index d4d6642a9..758a521ee 100644
--- a/tests/robot/__main__.py
+++ b/tests/robot/__main__.py
@@ -16,7 +16,7 @@ import tests as searx_tests
 from tests.robot import test_webapp
 
 
-class SearxRobotLayer():
+class SearxRobotLayer:
     """Searx Robot Test Layer"""
 
     def setUp(self):
@@ -42,9 +42,7 @@ class SearxRobotLayer():
 
         # run the server
         self.server = subprocess.Popen(  # pylint: disable=consider-using-with
-            [exe, webapp],
-            stdout=subprocess.PIPE,
-            stderr=subprocess.STDOUT
+            [exe, webapp], stdout=subprocess.PIPE, stderr=subprocess.STDOUT
         )
         if hasattr(self.server.stdout, 'read1'):
             print(self.server.stdout.read1(1024).decode())
diff --git a/tests/unit/__init__.py b/tests/unit/__init__.py
index d1c97ec81..9094e836a 100644
--- a/tests/unit/__init__.py
+++ b/tests/unit/__init__.py
@@ -2,5 +2,4 @@ import os
 from os.path import dirname, sep, abspath
 
 # In unit tests the user settings from unit/settings/test_settings.yml are used.
-os.environ['SEARXNG_SETTINGS_PATH'] = abspath(
-    dirname(__file__) + sep + 'settings' + sep + 'test_settings.yml')
+os.environ['SEARXNG_SETTINGS_PATH'] = abspath(dirname(__file__) + sep + 'settings' + sep + 'test_settings.yml')
diff --git a/tests/unit/engines/test_command.py b/tests/unit/engines/test_command.py
index d2bb123f7..7876dd55e 100644
--- a/tests/unit/engines/test_command.py
+++ b/tests/unit/engines/test_command.py
@@ -114,7 +114,6 @@ INFO:werkzeug: * Debugger PIN: 299-578-362'''
                     'template': 'key-value.html',
                     'level': 'DEBUG',
                 },
-
             ],
             [
                 {
@@ -136,7 +135,6 @@ INFO:werkzeug: * Debugger PIN: 299-578-362'''
                     'level': 'INFO',
                 },
             ],
-
         ]
 
         for i in [0, 1]:
@@ -171,7 +169,7 @@ commit '''
             'commit': '\w{40}',
             'author': '[\w* ]* <\w*@?\w*\.?\w*>',
             'date': 'Date: .*',
-            'message': '\n\n.*$'
+            'message': '\n\n.*$',
         }
         expected_results = [
             {
@@ -195,7 +193,6 @@ commit '''
                 'message': '\n\nthird interesting message',
                 'template': 'key-value.html',
             },
-
         ]
 
         results = git_log_engine.search(''.encode('utf-8'), {'pageno': 1})
diff --git a/tests/unit/engines/test_xpath.py b/tests/unit/engines/test_xpath.py
index 287beeab4..e616ff025 100644
--- a/tests/unit/engines/test_xpath.py
+++ b/tests/unit/engines/test_xpath.py
@@ -6,7 +6,6 @@ from tests import SearxTestCase
 
 
 class TestXpathEngine(SearxTestCase):
-
     def test_request(self):
         xpath.search_url = 'https://url.com/{query}'
         xpath.categories = []
diff --git a/tests/unit/network/test_network.py b/tests/unit/network/test_network.py
index 02628760b..d25a0d77b 100644
--- a/tests/unit/network/test_network.py
+++ b/tests/unit/network/test_network.py
@@ -9,7 +9,6 @@ from tests import SearxTestCase
 
 
 class TestNetwork(SearxTestCase):
-
     def setUp(self):
         initialize()
 
@@ -51,23 +50,23 @@ class TestNetwork(SearxTestCase):
         network = Network(proxies='http://localhost:1337')
         self.assertEqual(next(network._proxies_cycle), (('all://', 'http://localhost:1337'),))
 
-        network = Network(proxies={
-            'https': 'http://localhost:1337',
-            'http': 'http://localhost:1338'
-        })
-        self.assertEqual(next(network._proxies_cycle),
-                         (('https://', 'http://localhost:1337'), ('http://', 'http://localhost:1338')))
-        self.assertEqual(next(network._proxies_cycle),
-                         (('https://', 'http://localhost:1337'), ('http://', 'http://localhost:1338')))
-
-        network = Network(proxies={
-            'https': ['http://localhost:1337', 'http://localhost:1339'],
-            'http': 'http://localhost:1338'
-        })
-        self.assertEqual(next(network._proxies_cycle),
-                         (('https://', 'http://localhost:1337'), ('http://', 'http://localhost:1338')))
-        self.assertEqual(next(network._proxies_cycle),
-                         (('https://', 'http://localhost:1339'), ('http://', 'http://localhost:1338')))
+        network = Network(proxies={'https': 'http://localhost:1337', 'http': 'http://localhost:1338'})
+        self.assertEqual(
+            next(network._proxies_cycle), (('https://', 'http://localhost:1337'), ('http://', 'http://localhost:1338'))
+        )
+        self.assertEqual(
+            next(network._proxies_cycle), (('https://', 'http://localhost:1337'), ('http://', 'http://localhost:1338'))
+        )
+
+        network = Network(
+            proxies={'https': ['http://localhost:1337', 'http://localhost:1339'], 'http': 'http://localhost:1338'}
+        )
+        self.assertEqual(
+            next(network._proxies_cycle), (('https://', 'http://localhost:1337'), ('http://', 'http://localhost:1338'))
+        )
+        self.assertEqual(
+            next(network._proxies_cycle), (('https://', 'http://localhost:1339'), ('http://', 'http://localhost:1338'))
+        )
 
         with self.assertRaises(ValueError):
             Network(proxies=1)
@@ -134,6 +133,7 @@ class TestNetworkRequestRetries(SearxTestCase):
                 first = False
                 return httpx.Response(status_code=403, text=TestNetworkRequestRetries.TEXT)
             return httpx.Response(status_code=200, text=TestNetworkRequestRetries.TEXT)
+
         return get_response
 
     async def test_retries_ok(self):
@@ -206,6 +206,7 @@ class TestNetworkStreamRetries(SearxTestCase):
                 first = False
                 raise httpx.RequestError('fake exception', request=None)
             return httpx.Response(status_code=200, text=TestNetworkStreamRetries.TEXT)
+
         return stream
 
     async def test_retries_ok(self):
diff --git a/tests/unit/test_answerers.py b/tests/unit/test_answerers.py
index 1119b697d..73148f327 100644
--- a/tests/unit/test_answerers.py
+++ b/tests/unit/test_answerers.py
@@ -7,7 +7,6 @@ from tests import SearxTestCase
 
 
 class AnswererTest(SearxTestCase):
-
     def test_unicode_input(self):
         query = Mock()
         unicode_payload = 'árvíztűrő tükörfúrógép'
diff --git a/tests/unit/test_engines_init.py b/tests/unit/test_engines_init.py
index dffeaf8e8..c72f5c8e5 100644
--- a/tests/unit/test_engines_init.py
+++ b/tests/unit/test_engines_init.py
@@ -3,15 +3,16 @@ from tests import SearxTestCase
 
 
 class TestEnginesInit(SearxTestCase):
-
     @classmethod
     def tearDownClass(cls):
         settings['outgoing']['using_tor_proxy'] = False
         settings['outgoing']['extra_proxy_timeout'] = 0
 
     def test_initialize_engines_default(self):
-        engine_list = [{'engine': 'dummy', 'name': 'engine1', 'shortcut': 'e1'},
-                       {'engine': 'dummy', 'name': 'engine2', 'shortcut': 'e2'}]
+        engine_list = [
+            {'engine': 'dummy', 'name': 'engine1', 'shortcut': 'e1'},
+            {'engine': 'dummy', 'name': 'engine2', 'shortcut': 'e2'},
+        ]
 
         engines.load_engines(engine_list)
         self.assertEqual(len(engines.engines), 2)
@@ -20,8 +21,10 @@ class TestEnginesInit(SearxTestCase):
 
     def test_initialize_engines_exclude_onions(self):
         settings['outgoing']['using_tor_proxy'] = False
-        engine_list = [{'engine': 'dummy', 'name': 'engine1', 'shortcut': 'e1', 'categories': 'general'},
-                       {'engine': 'dummy', 'name': 'engine2', 'shortcut': 'e2', 'categories': 'onions'}]
+        engine_list = [
+            {'engine': 'dummy', 'name': 'engine1', 'shortcut': 'e1', 'categories': 'general'},
+            {'engine': 'dummy', 'name': 'engine2', 'shortcut': 'e2', 'categories': 'onions'},
+        ]
 
         engines.load_engines(engine_list)
         self.assertEqual(len(engines.engines), 1)
@@ -31,9 +34,17 @@ class TestEnginesInit(SearxTestCase):
     def test_initialize_engines_include_onions(self):
         settings['outgoing']['using_tor_proxy'] = True
         settings['outgoing']['extra_proxy_timeout'] = 100.0
-        engine_list = [{'engine': 'dummy', 'name': 'engine1', 'shortcut': 'e1', 'categories': 'general',
-                        'timeout': 20.0, 'onion_url': 'http://engine1.onion'},
-                       {'engine': 'dummy', 'name': 'engine2', 'shortcut': 'e2', 'categories': 'onions'}]
+        engine_list = [
+            {
+                'engine': 'dummy',
+                'name': 'engine1',
+                'shortcut': 'e1',
+                'categories': 'general',
+                'timeout': 20.0,
+                'onion_url': 'http://engine1.onion',
+            },
+            {'engine': 'dummy', 'name': 'engine2', 'shortcut': 'e2', 'categories': 'onions'},
+        ]
 
         engines.load_engines(engine_list)
         self.assertEqual(len(engines.engines), 2)
diff --git a/tests/unit/test_external_bangs.py b/tests/unit/test_external_bangs.py
index 68b3b5a78..698ce36c6 100644
--- a/tests/unit/test_external_bangs.py
+++ b/tests/unit/test_external_bangs.py
@@ -18,9 +18,9 @@ TEST_DB = {
             's': {
                 'on': 'season' + chr(2) + chr(1) + '0',
                 'capes': 'seascape' + chr(2) + chr(1) + '0',
-            }
+            },
         },
-        'error': ['error in external_bangs.json']
+        'error': ['error in external_bangs.json'],
     }
 }
 
@@ -57,7 +57,6 @@ class TestGetNode(SearxTestCase):
 
 
 class TestResolveBangDefinition(SearxTestCase):
-
     def test_https(self):
         url, rank = resolve_bang_definition('//example.com/' + chr(2) + chr(1) + '42', 'query')
         self.assertEqual(url, 'https://example.com/query')
@@ -70,7 +69,6 @@ class TestResolveBangDefinition(SearxTestCase):
 
 
 class TestGetBangDefinitionAndAutocomplete(SearxTestCase):
-
     def test_found(self):
         bang_definition, new_autocomplete = get_bang_definition_and_autocomplete('exam', external_bangs_db=TEST_DB)
         self.assertEqual(bang_definition, TEST_DB['trie']['exam']['*'])
@@ -103,7 +101,6 @@ class TestGetBangDefinitionAndAutocomplete(SearxTestCase):
 
 
 class TestExternalBangJson(SearxTestCase):
-
     def test_no_external_bang_query(self):
         result = get_bang_url(SearchQuery('test', engineref_list=[EngineRef('wikipedia', 'general')]))
         self.assertEqual(result, None)
diff --git a/tests/unit/test_plugins.py b/tests/unit/test_plugins.py
index 5bad4e5c4..28df835e5 100644
--- a/tests/unit/test_plugins.py
+++ b/tests/unit/test_plugins.py
@@ -6,18 +6,16 @@ from tests import SearxTestCase
 
 
 def get_search_mock(query, **kwargs):
-    return Mock(search_query=Mock(query=query, **kwargs),
-                result_container=Mock(answers=dict()))
+    return Mock(search_query=Mock(query=query, **kwargs), result_container=Mock(answers=dict()))
 
 
-class PluginMock():
+class PluginMock:
     default_on = False
     name = 'Default plugin'
     description = 'Default plugin description'
 
 
 class PluginStoreTest(SearxTestCase):
-
     def test_PluginStore_init(self):
         store = plugins.PluginStore()
         self.assertTrue(isinstance(store.plugins, list) and len(store.plugins) == 0)
@@ -44,7 +42,6 @@ class PluginStoreTest(SearxTestCase):
 
 
 class SelfIPTest(SearxTestCase):
-
     def test_PluginStore_init(self):
         plugin = plugins.load_and_initialize_plugin('searx.plugins.self_info', False, (None, {}))
         store = plugins.PluginStore()
@@ -93,7 +90,6 @@ class SelfIPTest(SearxTestCase):
 
 
 class HashPluginTest(SearxTestCase):
-
     def test_PluginStore_init(self):
         store = plugins.PluginStore()
         plugin = plugins.load_and_initialize_plugin('searx.plugins.hash_plugin', False, (None, {}))
@@ -107,8 +103,9 @@ class HashPluginTest(SearxTestCase):
         # MD5
         search = get_search_mock(query='md5 test', pageno=1)
         store.call(store.plugins, 'post_search', request, search)
-        self.assertTrue('md5 hash digest: 098f6bcd4621d373cade4e832627b4f6'
-                        in search.result_container.answers['hash']['answer'])
+        self.assertTrue(
+            'md5 hash digest: 098f6bcd4621d373cade4e832627b4f6' in search.result_container.answers['hash']['answer']
+        )
 
         search = get_search_mock(query=b'md5 test', pageno=2)
         store.call(store.plugins, 'post_search', request, search)
@@ -117,31 +114,41 @@ class HashPluginTest(SearxTestCase):
         # SHA1
         search = get_search_mock(query='sha1 test', pageno=1)
         store.call(store.plugins, 'post_search', request, search)
-        self.assertTrue('sha1 hash digest: a94a8fe5ccb19ba61c4c0873d391e9879'
-                        '82fbbd3' in search.result_container.answers['hash']['answer'])
+        self.assertTrue(
+            'sha1 hash digest: a94a8fe5ccb19ba61c4c0873d391e9879'
+            '82fbbd3' in search.result_container.answers['hash']['answer']
+        )
 
         # SHA224
         search = get_search_mock(query='sha224 test', pageno=1)
         store.call(store.plugins, 'post_search', request, search)
-        self.assertTrue('sha224 hash digest: 90a3ed9e32b2aaf4c61c410eb9254261'
-                        '19e1a9dc53d4286ade99a809' in search.result_container.answers['hash']['answer'])
+        self.assertTrue(
+            'sha224 hash digest: 90a3ed9e32b2aaf4c61c410eb9254261'
+            '19e1a9dc53d4286ade99a809' in search.result_container.answers['hash']['answer']
+        )
 
         # SHA256
         search = get_search_mock(query='sha256 test', pageno=1)
         store.call(store.plugins, 'post_search', request, search)
-        self.assertTrue('sha256 hash digest: 9f86d081884c7d659a2feaa0c55ad015a'
-                        '3bf4f1b2b0b822cd15d6c15b0f00a08' in search.result_container.answers['hash']['answer'])
+        self.assertTrue(
+            'sha256 hash digest: 9f86d081884c7d659a2feaa0c55ad015a'
+            '3bf4f1b2b0b822cd15d6c15b0f00a08' in search.result_container.answers['hash']['answer']
+        )
 
         # SHA384
         search = get_search_mock(query='sha384 test', pageno=1)
         store.call(store.plugins, 'post_search', request, search)
-        self.assertTrue('sha384 hash digest: 768412320f7b0aa5812fce428dc4706b3c'
-                        'ae50e02a64caa16a782249bfe8efc4b7ef1ccb126255d196047dfedf1'
-                        '7a0a9' in search.result_container.answers['hash']['answer'])
+        self.assertTrue(
+            'sha384 hash digest: 768412320f7b0aa5812fce428dc4706b3c'
+            'ae50e02a64caa16a782249bfe8efc4b7ef1ccb126255d196047dfedf1'
+            '7a0a9' in search.result_container.answers['hash']['answer']
+        )
 
         # SHA512
         search = get_search_mock(query='sha512 test', pageno=1)
         store.call(store.plugins, 'post_search', request, search)
-        self.assertTrue('sha512 hash digest: ee26b0dd4af7e749aa1a8ee3c10ae9923f6'
-                        '18980772e473f8819a5d4940e0db27ac185f8a0e1d5f84f88bc887fd67b143732c304cc5'
-                        'fa9ad8e6f57f50028a8ff' in search.result_container.answers['hash']['answer'])
+        self.assertTrue(
+            'sha512 hash digest: ee26b0dd4af7e749aa1a8ee3c10ae9923f6'
+            '18980772e473f8819a5d4940e0db27ac185f8a0e1d5f84f88bc887fd67b143732c304cc5'
+            'fa9ad8e6f57f50028a8ff' in search.result_container.answers['hash']['answer']
+        )
diff --git a/tests/unit/test_preferences.py b/tests/unit/test_preferences.py
index 903b9b54d..1ffed5c1a 100644
--- a/tests/unit/test_preferences.py
+++ b/tests/unit/test_preferences.py
@@ -1,10 +1,16 @@
-from searx.preferences import (EnumStringSetting, MapSetting, MissingArgumentException, SearchLanguageSetting,
-                               MultipleChoiceSetting, PluginsSetting, ValidationException)
+from searx.preferences import (
+    EnumStringSetting,
+    MapSetting,
+    MissingArgumentException,
+    SearchLanguageSetting,
+    MultipleChoiceSetting,
+    PluginsSetting,
+    ValidationException,
+)
 from tests import SearxTestCase
 
 
 class PluginStub:
-
     def __init__(self, plugin_id, default_on):
         self.id = plugin_id
         self.default_on = default_on
@@ -121,20 +127,23 @@ class TestSettings(SearxTestCase):
 
 
 class TestPreferences(SearxTestCase):
-
     def test_encode(self):
         from searx.preferences import Preferences
+
         pref = Preferences(['oscar'], ['general'], {}, [])
-        url_params = 'eJx1VMmO2zAM_Zr6YrTocujJh6JF0QEKzKAz7VVgJNohLIseUU7ivy-VcWy5yyGOTVGP73GLKJNPYjiYgGeT4NB8BS9YOSY' \
-            'TUdifMDYM-vmGY1d5CN0EHTYOK88W_PXNkcDBozOjnzoK0vyi4bWnHs2RU4-zvHr_-RF9a-5Cy3GARByy7X7EkKMoBeMp9CuPQ-SzYMx' \
-            '8Vr9P1qKI-XJ_p1fOkRJWNCgVM0a-zAttmBJbHkaPSZlNts-_jiuBFgUh2mPztkpHHLBhsRArDHvm356eHh5vATS0Mqagr0ZsZO_V8hT' \
-            'B9srt54_v6jewJugqL4Nn_hYSdhxnI-jRpi05GDQCStOT7UGVmJY8ZnltRKyF23SGiLWjqNcygKGkpyeGZIywJfD1gI5AjRTAmBM55Aw' \
-            'Q0Tn626lj7jzWo4e5hnEsIlprX6dTgdBRpyRBFKTDgBF8AasVyT4gvSTEoXRpXWRyG3CYQYld65I_V6lboILTMAlZY65_ejRDcHgp0Tv' \
-            'EPtGAsqTiBf3m76g7pP9B84mwjPvuUtASRDei1nDF2ix_JXW91UJkXrPh6RAhznVmKyQl7dwJdMJ6bz1QOmgzYlrEzHDMcEUuo44AgS1' \
-            'CvkjaOb2Q2AyY5oGDTs_OLXE_c2I5cg9hk3kEJZ0fu4SuktsIA2RhuJwP86AdripThCBeO9uVUejyPGmFSxPrqEYcuWi25zOEXV9tc1m' \
-            '_KP1nafYtdfv6Q9hKfWmGm9A_3G635UwiVndLGdFCiLWkONk0xUxGLGGweGWTa2nZYZ0fS1YKlE3Uuw8fPl52E5U8HJYbC7sbjXUsrnT' \
+        url_params = (
+            'eJx1VMmO2zAM_Zr6YrTocujJh6JF0QEKzKAz7VVgJNohLIseUU7ivy-VcWy5yyGOTVGP73GLKJNPYjiYgGeT4NB8BS9YOSY'
+            'TUdifMDYM-vmGY1d5CN0EHTYOK88W_PXNkcDBozOjnzoK0vyi4bWnHs2RU4-zvHr_-RF9a-5Cy3GARByy7X7EkKMoBeMp9CuPQ-SzYMx'
+            '8Vr9P1qKI-XJ_p1fOkRJWNCgVM0a-zAttmBJbHkaPSZlNts-_jiuBFgUh2mPztkpHHLBhsRArDHvm356eHh5vATS0Mqagr0ZsZO_V8hT'
+            'B9srt54_v6jewJugqL4Nn_hYSdhxnI-jRpi05GDQCStOT7UGVmJY8ZnltRKyF23SGiLWjqNcygKGkpyeGZIywJfD1gI5AjRTAmBM55Aw'
+            'Q0Tn626lj7jzWo4e5hnEsIlprX6dTgdBRpyRBFKTDgBF8AasVyT4gvSTEoXRpXWRyG3CYQYld65I_V6lboILTMAlZY65_ejRDcHgp0Tv'
+            'EPtGAsqTiBf3m76g7pP9B84mwjPvuUtASRDei1nDF2ix_JXW91UJkXrPh6RAhznVmKyQl7dwJdMJ6bz1QOmgzYlrEzHDMcEUuo44AgS1'
+            'CvkjaOb2Q2AyY5oGDTs_OLXE_c2I5cg9hk3kEJZ0fu4SuktsIA2RhuJwP86AdripThCBeO9uVUejyPGmFSxPrqEYcuWi25zOEXV9tc1m'
+            '_KP1nafYtdfv6Q9hKfWmGm9A_3G635UwiVndLGdFCiLWkONk0xUxGLGGweGWTa2nZYZ0fS1YKlE3Uuw8fPl52E5U8HJYbC7sbjXUsrnT'
             'XHXRbELfO-1fGSqskiGnMK7B0dV3t8Lq08pbdtYpuVdoKWA2Yjuyah_vHp2rZWjo0zXL8Gw8DTj0='
+        )
         pref.parse_encoded_data(url_params)
         self.assertEqual(
             vars(pref.key_value_settings['categories']),
-            {'value': ['general'], 'locked': False, 'choices': ['general', 'none']})
+            {'value': ['general'], 'locked': False, 'choices': ['general', 'none']},
+        )
diff --git a/tests/unit/test_query.py b/tests/unit/test_query.py
index edb0a18f7..9a53f8f47 100644
--- a/tests/unit/test_query.py
+++ b/tests/unit/test_query.py
@@ -17,7 +17,6 @@ TEST_ENGINES = [
 
 
 class TestQuery(SearxTestCase):
-
     def test_simple_query(self):
         query_text = 'the query'
         query = RawTextQuery(query_text, [])
@@ -58,7 +57,6 @@ class TestQuery(SearxTestCase):
 
 
 class TestLanguageParser(SearxTestCase):
-
     def test_language_code(self):
         language = 'es-ES'
         query_text = 'the query'
@@ -136,7 +134,6 @@ class TestLanguageParser(SearxTestCase):
 
 
 class TestTimeoutParser(SearxTestCase):
-
     def test_timeout_below100(self):
         query_text = '<3 the query'
         query = RawTextQuery(query_text, [])
@@ -189,7 +186,6 @@ class TestTimeoutParser(SearxTestCase):
 
 
 class TestExternalBangParser(SearxTestCase):
-
     def test_external_bang(self):
         query_text = '!!ddg the query'
         query = RawTextQuery(query_text, [])
diff --git a/tests/unit/test_results.py b/tests/unit/test_results.py
index aa99e78c7..113e9cd3c 100644
--- a/tests/unit/test_results.py
+++ b/tests/unit/test_results.py
@@ -4,10 +4,7 @@ from searx.results import ResultContainer
 from tests import SearxTestCase
 
 
-def fake_result(url='https://aa.bb/cc?dd=ee#ff',
-                title='aaa',
-                content='bbb',
-                engine='wikipedia', **kwargs):
+def fake_result(url='https://aa.bb/cc?dd=ee#ff', title='aaa', content='bbb', engine='wikipedia', **kwargs):
     result = {
         # fmt: off
         'url': url,
@@ -22,7 +19,6 @@ def fake_result(url='https://aa.bb/cc?dd=ee#ff',
 
 #  TODO
 class ResultContainerTestCase(SearxTestCase):
-
     def test_empty(self):
         c = ResultContainer()
         self.assertEqual(c.get_ordered_results(), [])
diff --git a/tests/unit/test_search.py b/tests/unit/test_search.py
index c7f15a681..fa16947be 100644
--- a/tests/unit/test_search.py
+++ b/tests/unit/test_search.py
@@ -22,11 +22,11 @@ TEST_ENGINES = [
 
 
 class SearchQueryTestCase(SearxTestCase):
-
     def test_repr(self):
         s = SearchQuery('test', [EngineRef('bing', 'general')], 'all', 0, 1, '1', 5.0, 'g')
-        self.assertEqual(repr(s),
-                         "SearchQuery('test', [EngineRef('bing', 'general')], 'all', 0, 1, '1', 5.0, 'g')")  # noqa
+        self.assertEqual(
+            repr(s), "SearchQuery('test', [EngineRef('bing', 'general')], 'all', 0, 1, '1', 5.0, 'g')"
+        )  # noqa
 
     def test_eq(self):
         s = SearchQuery('test', [EngineRef('bing', 'general')], 'all', 0, 1, None, None, None)
@@ -36,64 +36,80 @@ class SearchQueryTestCase(SearxTestCase):
 
 
 class SearchTestCase(SearxTestCase):
-
     @classmethod
     def setUpClass(cls):
         searx.search.initialize(TEST_ENGINES)
 
     def test_timeout_simple(self):
         settings['outgoing']['max_request_timeout'] = None
-        search_query = SearchQuery('test', [EngineRef(PUBLIC_ENGINE_NAME, 'general')],
-                                   'en-US', SAFESEARCH, PAGENO, None, None)
+        search_query = SearchQuery(
+            'test', [EngineRef(PUBLIC_ENGINE_NAME, 'general')], 'en-US', SAFESEARCH, PAGENO, None, None
+        )
         search = searx.search.Search(search_query)
         search.search()
         self.assertEqual(search.actual_timeout, 3.0)
 
     def test_timeout_query_above_default_nomax(self):
         settings['outgoing']['max_request_timeout'] = None
-        search_query = SearchQuery('test', [EngineRef(PUBLIC_ENGINE_NAME, 'general')],
-                                   'en-US', SAFESEARCH, PAGENO, None, 5.0)
+        search_query = SearchQuery(
+            'test', [EngineRef(PUBLIC_ENGINE_NAME, 'general')], 'en-US', SAFESEARCH, PAGENO, None, 5.0
+        )
         search = searx.search.Search(search_query)
         search.search()
         self.assertEqual(search.actual_timeout, 3.0)
 
     def test_timeout_query_below_default_nomax(self):
         settings['outgoing']['max_request_timeout'] = None
-        search_query = SearchQuery('test', [EngineRef(PUBLIC_ENGINE_NAME, 'general')],
-                                   'en-US', SAFESEARCH, PAGENO, None, 1.0)
+        search_query = SearchQuery(
+            'test', [EngineRef(PUBLIC_ENGINE_NAME, 'general')], 'en-US', SAFESEARCH, PAGENO, None, 1.0
+        )
         search = searx.search.Search(search_query)
         search.search()
         self.assertEqual(search.actual_timeout, 1.0)
 
     def test_timeout_query_below_max(self):
         settings['outgoing']['max_request_timeout'] = 10.0
-        search_query = SearchQuery('test', [EngineRef(PUBLIC_ENGINE_NAME, 'general')],
-                                   'en-US', SAFESEARCH, PAGENO, None, 5.0)
+        search_query = SearchQuery(
+            'test', [EngineRef(PUBLIC_ENGINE_NAME, 'general')], 'en-US', SAFESEARCH, PAGENO, None, 5.0
+        )
         search = searx.search.Search(search_query)
         search.search()
         self.assertEqual(search.actual_timeout, 5.0)
 
     def test_timeout_query_above_max(self):
         settings['outgoing']['max_request_timeout'] = 10.0
-        search_query = SearchQuery('test', [EngineRef(PUBLIC_ENGINE_NAME, 'general')],
-                                   'en-US', SAFESEARCH, PAGENO, None, 15.0)
+        search_query = SearchQuery(
+            'test', [EngineRef(PUBLIC_ENGINE_NAME, 'general')], 'en-US', SAFESEARCH, PAGENO, None, 15.0
+        )
         search = searx.search.Search(search_query)
         search.search()
         self.assertEqual(search.actual_timeout, 10.0)
 
     def test_external_bang(self):
-        search_query = SearchQuery('yes yes',
-                                   [EngineRef(PUBLIC_ENGINE_NAME, 'general')],
-                                   'en-US', SAFESEARCH, PAGENO, None, None,
-                                   external_bang="yt")
+        search_query = SearchQuery(
+            'yes yes',
+            [EngineRef(PUBLIC_ENGINE_NAME, 'general')],
+            'en-US',
+            SAFESEARCH,
+            PAGENO,
+            None,
+            None,
+            external_bang="yt",
+        )
         search = searx.search.Search(search_query)
         results = search.search()
         # For checking if the user redirected with the youtube external bang
         self.assertTrue(results.redirect_url is not None)
 
-        search_query = SearchQuery('youtube never gonna give you up',
-                                   [EngineRef(PUBLIC_ENGINE_NAME, 'general')],
-                                   'en-US', SAFESEARCH, PAGENO, None, None)
+        search_query = SearchQuery(
+            'youtube never gonna give you up',
+            [EngineRef(PUBLIC_ENGINE_NAME, 'general')],
+            'en-US',
+            SAFESEARCH,
+            PAGENO,
+            None,
+            None,
+        )
 
         search = searx.search.Search(search_query)
         results = search.search()
diff --git a/tests/unit/test_settings_loader.py b/tests/unit/test_settings_loader.py
index 9e04df653..13a2d4f37 100644
--- a/tests/unit/test_settings_loader.py
+++ b/tests/unit/test_settings_loader.py
@@ -12,7 +12,6 @@ test_dir = abspath(dirname(__file__))
 
 
 class TestLoad(SearxTestCase):
-
     def test_load_zero(self):
         with self.assertRaises(SearxSettingsException):
             settings_loader.load_yaml('/dev/zero')
@@ -31,7 +30,6 @@ class TestLoad(SearxTestCase):
 
 
 class TestDefaultSettings(SearxTestCase):
-
     def test_load(self):
         settings, msg = settings_loader.load_settings(load_user_setttings=False)
         self.assertTrue(msg.startswith('load the default settings from'))
@@ -46,7 +44,6 @@ class TestDefaultSettings(SearxTestCase):
 
 
 class TestUserSettings(SearxTestCase):
-
     def test_is_use_default_settings(self):
         self.assertFalse(settings_loader.is_use_default_settings({}))
         self.assertTrue(settings_loader.is_use_default_settings({'use_default_settings': True}))
@@ -57,23 +54,24 @@ class TestUserSettings(SearxTestCase):
             self.assertFalse(settings_loader.is_use_default_settings({'use_default_settings': 0}))
 
     def test_user_settings_not_found(self):
-        with patch.dict(settings_loader.environ,
-                        {'SEARXNG_SETTINGS_PATH': '/dev/null'}):
+        with patch.dict(settings_loader.environ, {'SEARXNG_SETTINGS_PATH': '/dev/null'}):
             settings, msg = settings_loader.load_settings()
             self.assertTrue(msg.startswith('load the default settings from'))
             self.assertEqual(settings['server']['secret_key'], "ultrasecretkey")
 
     def test_user_settings(self):
-        with patch.dict(settings_loader.environ,
-                        {'SEARXNG_SETTINGS_PATH': join(test_dir, 'settings/user_settings_simple.yml')}):
+        with patch.dict(
+            settings_loader.environ, {'SEARXNG_SETTINGS_PATH': join(test_dir, 'settings/user_settings_simple.yml')}
+        ):
             settings, msg = settings_loader.load_settings()
             self.assertTrue(msg.startswith('merge the default settings'))
             self.assertEqual(settings['server']['secret_key'], "user_secret_key")
             self.assertEqual(settings['server']['default_http_headers']['Custom-Header'], "Custom-Value")
 
     def test_user_settings_remove(self):
-        with patch.dict(settings_loader.environ,
-                        {'SEARXNG_SETTINGS_PATH': join(test_dir, 'settings/user_settings_remove.yml')}):
+        with patch.dict(
+            settings_loader.environ, {'SEARXNG_SETTINGS_PATH': join(test_dir, 'settings/user_settings_remove.yml')}
+        ):
             settings, msg = settings_loader.load_settings()
             self.assertTrue(msg.startswith('merge the default settings'))
             self.assertEqual(settings['server']['secret_key'], "user_secret_key")
@@ -84,8 +82,9 @@ class TestUserSettings(SearxTestCase):
             self.assertIn('wikipedia', engine_names)
 
     def test_user_settings_remove2(self):
-        with patch.dict(settings_loader.environ,
-                        {'SEARXNG_SETTINGS_PATH': join(test_dir, 'settings/user_settings_remove2.yml')}):
+        with patch.dict(
+            settings_loader.environ, {'SEARXNG_SETTINGS_PATH': join(test_dir, 'settings/user_settings_remove2.yml')}
+        ):
             settings, msg = settings_loader.load_settings()
             self.assertTrue(msg.startswith('merge the default settings'))
             self.assertEqual(settings['server']['secret_key'], "user_secret_key")
@@ -101,8 +100,9 @@ class TestUserSettings(SearxTestCase):
             self.assertEqual(newengine[0]['engine'], 'dummy')
 
     def test_user_settings_keep_only(self):
-        with patch.dict(settings_loader.environ,
-                        {'SEARXNG_SETTINGS_PATH': join(test_dir, 'settings/user_settings_keep_only.yml')}):
+        with patch.dict(
+            settings_loader.environ, {'SEARXNG_SETTINGS_PATH': join(test_dir, 'settings/user_settings_keep_only.yml')}
+        ):
             settings, msg = settings_loader.load_settings()
             self.assertTrue(msg.startswith('merge the default settings'))
             engine_names = [engine['name'] for engine in settings['engines']]
@@ -111,8 +111,9 @@ class TestUserSettings(SearxTestCase):
             self.assertEqual(len(settings['engines'][2]), 1)
 
     def test_custom_settings(self):
-        with patch.dict(settings_loader.environ,
-                        {'SEARXNG_SETTINGS_PATH': join(test_dir, 'settings/user_settings.yml')}):
+        with patch.dict(
+            settings_loader.environ, {'SEARXNG_SETTINGS_PATH': join(test_dir, 'settings/user_settings.yml')}
+        ):
             settings, msg = settings_loader.load_settings()
             self.assertTrue(msg.startswith('load the user settings from'))
             self.assertEqual(settings['server']['port'], 9000)
diff --git a/tests/unit/test_standalone_searx.py b/tests/unit/test_standalone_searx.py
index c81598160..a3d8b4d4f 100644
--- a/tests/unit/test_standalone_searx.py
+++ b/tests/unit/test_standalone_searx.py
@@ -23,8 +23,7 @@ class StandaloneSearx(SearxTestCase):
 
     def test_parse_argument_no_args(self):
         """Test parse argument without args."""
-        with patch.object(sys, 'argv', ['standalone_searx']), \
-                self.assertRaises(SystemExit):
+        with patch.object(sys, 'argv', ['standalone_searx']), self.assertRaises(SystemExit):
             sys.stderr = io.StringIO()
             sas.parse_argument()
             sys.stdout = sys.__stderr__
@@ -33,8 +32,13 @@ class StandaloneSearx(SearxTestCase):
         """Test parse argument with basic args."""
         query = 'red box'
         exp_dict = {
-            'query': query, 'category': 'general', 'lang': 'all', 'pageno': 1,
-            'safesearch': '0', 'timerange': None}
+            'query': query,
+            'category': 'general',
+            'lang': 'all',
+            'pageno': 1,
+            'safesearch': '0',
+            'timerange': None,
+        }
         args = ['standalone_searx', query]
         with patch.object(sys, 'argv', args):
             res = sas.parse_argument()
@@ -45,16 +49,16 @@ class StandaloneSearx(SearxTestCase):
     def test_to_dict(self):
         """test to_dict."""
         self.assertEqual(
-            sas.to_dict(
-                sas.get_search_query(sas.parse_argument(['red box']))),
+            sas.to_dict(sas.get_search_query(sas.parse_argument(['red box']))),
             {
-                'search': {
-                    'q': 'red box', 'pageno': 1, 'lang': 'all',
-                    'safesearch': 0, 'timerange': None
-                },
-                'results': [], 'infoboxes': [], 'suggestions': [],
-                'answers': [], 'paging': False, 'results_number': 0
-            }
+                'search': {'q': 'red box', 'pageno': 1, 'lang': 'all', 'safesearch': 0, 'timerange': None},
+                'results': [],
+                'infoboxes': [],
+                'suggestions': [],
+                'answers': [],
+                'paging': False,
+                'results_number': 0,
+            },
         )
 
     def test_to_dict_with_mock(self):
@@ -77,30 +81,28 @@ class StandaloneSearx(SearxTestCase):
                         'safesearch': m_sq.safesearch,
                         'timerange': m_sq.time_range,
                     },
-                    'suggestions': []
-                }
+                    'suggestions': [],
+                },
             )
 
     def test_get_search_query(self):
         """test get_search_query."""
-        args = sas.parse_argument(['rain', ])
+        args = sas.parse_argument(
+            [
+                'rain',
+            ]
+        )
         search_q = sas.get_search_query(args)
         self.assertTrue(search_q)
-        self.assertEqual(search_q, SearchQuery('rain', [EngineRef('engine1', 'general')],
-                         'all', 0, 1, None, None, None))
+        self.assertEqual(
+            search_q, SearchQuery('rain', [EngineRef('engine1', 'general')], 'all', 0, 1, None, None, None)
+        )
 
     def test_no_parsed_url(self):
         """test no_parsed_url func"""
-        self.assertEqual(
-            sas.no_parsed_url([{'parsed_url': 'http://example.com'}]),
-            [{}]
-        )
+        self.assertEqual(sas.no_parsed_url([{'parsed_url': 'http://example.com'}]), [{}])
 
-    @params(
-        (datetime.datetime(2020, 1, 1), '2020-01-01T00:00:00'),
-        ('a'.encode('utf8'), 'a'),
-        (set([1]), [1])
-    )
+    @params((datetime.datetime(2020, 1, 1), '2020-01-01T00:00:00'), ('a'.encode('utf8'), 'a'), (set([1]), [1]))
     def test_json_serial(self, arg, exp_res):
         """test json_serial func"""
         self.assertEqual(sas.json_serial(arg), exp_res)
diff --git a/tests/unit/test_utils.py b/tests/unit/test_utils.py
index bea28c0cc..3b79797e3 100644
--- a/tests/unit/test_utils.py
+++ b/tests/unit/test_utils.py
@@ -9,7 +9,6 @@ from tests import SearxTestCase
 
 
 class TestUtils(SearxTestCase):
-
     def test_gen_useragent(self):
         self.assertIsInstance(utils.gen_useragent(), str)
         self.assertIsNotNone(utils.gen_useragent())
@@ -73,6 +72,7 @@ class TestUtils(SearxTestCase):
     def test_extract_url(self):
         def f(html_str, search_url):
             return utils.extract_url(html.fromstring(html_str), search_url)
+
         self.assertEqual(f('<span id="42">https://example.com</span>', 'http://example.com/'), 'https://example.com/')
         self.assertEqual(f('https://example.com', 'http://example.com/'), 'https://example.com/')
         self.assertEqual(f('//example.com', 'http://example.com/'), 'http://example.com/')
@@ -122,14 +122,11 @@ class TestUtils(SearxTestCase):
 
     def test_ecma_unscape(self):
         self.assertEqual(utils.ecma_unescape('text%20with%20space'), 'text with space')
-        self.assertEqual(utils.ecma_unescape('text using %xx: %F3'),
-                         'text using %xx: ó')
-        self.assertEqual(utils.ecma_unescape('text using %u: %u5409, %u4E16%u754c'),
-                         'text using %u: 吉, 世界')
+        self.assertEqual(utils.ecma_unescape('text using %xx: %F3'), 'text using %xx: ó')
+        self.assertEqual(utils.ecma_unescape('text using %u: %u5409, %u4E16%u754c'), 'text using %u: 吉, 世界')
 
 
 class TestHTMLTextExtractor(SearxTestCase):
-
     def setUp(self):
         self.html_text_extractor = utils.HTMLTextExtractor()
 
diff --git a/tests/unit/test_webadapter.py b/tests/unit/test_webadapter.py
index 9d8ff5f28..975d846cc 100644
--- a/tests/unit/test_webadapter.py
+++ b/tests/unit/test_webadapter.py
@@ -25,7 +25,6 @@ SEARCHQUERY = [EngineRef(PRIVATE_ENGINE_NAME, 'general')]
 
 
 class ValidateQueryCase(SearxTestCase):
-
     @classmethod
     def setUpClass(cls):
         searx.search.initialize(TEST_ENGINES)
diff --git a/tests/unit/test_webapp.py b/tests/unit/test_webapp.py
index 43b631cb8..920a346a5 100644
--- a/tests/unit/test_webapp.py
+++ b/tests/unit/test_webapp.py
@@ -10,11 +10,11 @@ from tests import SearxTestCase
 
 
 class ViewsTestCase(SearxTestCase):
-
     def setUp(self):
         # skip init function (no external HTTP request)
         def dummy(*args, **kwargs):
             pass
+
         self.setattr4test(searx.search.processors, 'initialize_processor', dummy)
 
         from searx import webapp  # pylint disable=import-outside-toplevel
@@ -30,43 +30,39 @@ class ViewsTestCase(SearxTestCase):
                 'url': 'http://first.test.xyz',
                 'engines': ['youtube', 'startpage'],
                 'engine': 'startpage',
-                'parsed_url': ParseResult(scheme='http', netloc='first.test.xyz', path='/', params='', query='', fragment=''),  # noqa
-            }, {
+                'parsed_url': ParseResult(
+                    scheme='http', netloc='first.test.xyz', path='/', params='', query='', fragment=''
+                ),  # noqa
+            },
+            {
                 'content': 'second test content',
                 'title': 'Second Test',
                 'url': 'http://second.test.xyz',
                 'engines': ['youtube', 'startpage'],
                 'engine': 'youtube',
-                'parsed_url': ParseResult(scheme='http', netloc='second.test.xyz', path='/', params='', query='', fragment=''),  # noqa
+                'parsed_url': ParseResult(
+                    scheme='http', netloc='second.test.xyz', path='/', params='', query='', fragment=''
+                ),  # noqa
             },
         ]
 
-        timings = [
-            {
-                'engine': 'startpage',
-                'total': 0.8,
-                'load': 0.7
-            },
-            {
-                'engine': 'youtube',
-                'total': 0.9,
-                'load': 0.6
-            }
-        ]
+        timings = [{'engine': 'startpage', 'total': 0.8, 'load': 0.7}, {'engine': 'youtube', 'total': 0.9, 'load': 0.6}]
 
         def search_mock(search_self, *args):
-            search_self.result_container = Mock(get_ordered_results=lambda: test_results,
-                                                answers=dict(),
-                                                corrections=set(),
-                                                suggestions=set(),
-                                                infoboxes=[],
-                                                unresponsive_engines=set(),
-                                                results=test_results,
-                                                results_number=lambda: 3,
-                                                results_length=lambda: len(test_results),
-                                                get_timings=lambda: timings,
-                                                redirect_url=None,
-                                                engine_data={})
+            search_self.result_container = Mock(
+                get_ordered_results=lambda: test_results,
+                answers=dict(),
+                corrections=set(),
+                suggestions=set(),
+                infoboxes=[],
+                unresponsive_engines=set(),
+                results=test_results,
+                results_number=lambda: 3,
+                results_length=lambda: len(test_results),
+                get_timings=lambda: timings,
+                redirect_url=None,
+                engine_data={},
+            )
 
         self.setattr4test(Search, 'search', search_mock)
 
@@ -82,9 +78,12 @@ class ViewsTestCase(SearxTestCase):
     def test_index_empty(self):
         result = self.app.post('/')
         self.assertEqual(result.status_code, 200)
-        self.assertIn(b'<div class="text-hide center-block" id="main-logo">'
-                      + b'<img class="center-block img-responsive" src="/static/themes/oscar/img/searxng.svg"'
-                      + b' alt="searx logo" />SearXNG</div>', result.data)
+        self.assertIn(
+            b'<div class="text-hide center-block" id="main-logo">'
+            + b'<img class="center-block img-responsive" src="/static/themes/oscar/img/searxng.svg"'
+            + b' alt="searx logo" />SearXNG</div>',
+            result.data,
+        )
 
     def test_index_html_post(self):
         result = self.app.post('/', data={'q': 'test'})
@@ -120,11 +119,10 @@ class ViewsTestCase(SearxTestCase):
             b'<h4 class="result_header" id="result-2"><img width="32" height="32" class="favicon"'
             + b' src="/static/themes/oscar/img/icons/youtube.png" alt="youtube" /><a href="http://second.test.xyz"'
             + b' rel="noreferrer" aria-labelledby="result-2">Second <span class="highlight">Test</span></a></h4>',  # noqa
-            result.data
+            result.data,
         )
         self.assertIn(
-            b'<p class="result-content">second <span class="highlight">test</span> content</p>',  # noqa
-            result.data
+            b'<p class="result-content">second <span class="highlight">test</span> content</p>', result.data  # noqa
         )
 
     def test_index_json(self):
@@ -151,7 +149,7 @@ class ViewsTestCase(SearxTestCase):
             b'title,url,content,host,engine,score,type\r\n'
             b'First Test,http://first.test.xyz,first test content,first.test.xyz,startpage,,result\r\n'  # noqa
             b'Second Test,http://second.test.xyz,second test content,second.test.xyz,youtube,,result\r\n',  # noqa
-            result.data
+            result.data,
         )
 
     def test_index_rss(self):
@@ -161,30 +159,15 @@ class ViewsTestCase(SearxTestCase):
     def test_search_rss(self):
         result = self.app.post('/search', data={'q': 'test', 'format': 'rss'})
 
-        self.assertIn(
-            b'<description>Search results for "test" - searx</description>',
-            result.data
-        )
+        self.assertIn(b'<description>Search results for "test" - searx</description>', result.data)
 
-        self.assertIn(
-            b'<opensearch:totalResults>3</opensearch:totalResults>',
-            result.data
-        )
+        self.assertIn(b'<opensearch:totalResults>3</opensearch:totalResults>', result.data)
 
-        self.assertIn(
-            b'<title>First Test</title>',
-            result.data
-        )
+        self.assertIn(b'<title>First Test</title>', result.data)
 
-        self.assertIn(
-            b'<link>http://first.test.xyz</link>',
-            result.data
-        )
+        self.assertIn(b'<link>http://first.test.xyz</link>', result.data)
 
-        self.assertIn(
-            b'<description>first test content</description>',
-            result.data
-        )
+        self.assertIn(b'<description>first test content</description>', result.data)
 
     def test_about(self):
         result = self.app.get('/about')
@@ -199,18 +182,9 @@ class ViewsTestCase(SearxTestCase):
     def test_preferences(self):
         result = self.app.get('/preferences')
         self.assertEqual(result.status_code, 200)
-        self.assertIn(
-            b'<form method="post" action="/preferences" id="search_form">',
-            result.data
-        )
-        self.assertIn(
-            b'<label class="col-sm-3 col-md-2" for="categories">Default categories</label>',
-            result.data
-        )
-        self.assertIn(
-            b'<label class="col-sm-3 col-md-2" for="locale">Interface language</label>',
-            result.data
-        )
+        self.assertIn(b'<form method="post" action="/preferences" id="search_form">', result.data)
+        self.assertIn(b'<label class="col-sm-3 col-md-2" for="categories">Default categories</label>', result.data)
+        self.assertIn(b'<label class="col-sm-3 col-md-2" for="locale">Interface language</label>', result.data)
 
     def test_browser_locale(self):
         result = self.app.get('/preferences', headers={'Accept-Language': 'zh-tw;q=0.8'})
@@ -218,30 +192,26 @@ class ViewsTestCase(SearxTestCase):
         self.assertIn(
             b'<option value="zh-Hant-TW" selected="selected">',
             result.data,
-            'Interface locale ignored browser preference.'
+            'Interface locale ignored browser preference.',
         )
         self.assertIn(
             b'<option value="zh-Hant-TW" selected="selected">',
             result.data,
-            'Search language ignored browser preference.'
+            'Search language ignored browser preference.',
         )
 
     def test_brower_empty_locale(self):
         result = self.app.get('/preferences', headers={'Accept-Language': ''})
         self.assertEqual(result.status_code, 200)
         self.assertIn(
-            b'<option value="en" selected="selected">',
-            result.data,
-            'Interface locale ignored browser preference.'
+            b'<option value="en" selected="selected">', result.data, 'Interface locale ignored browser preference.'
         )
 
     def test_locale_occitan(self):
         result = self.app.get('/preferences?locale=oc')
         self.assertEqual(result.status_code, 200)
         self.assertIn(
-            b'<option value="oc" selected="selected">',
-            result.data,
-            'Interface locale ignored browser preference.'
+            b'<option value="oc" selected="selected">', result.data, 'Interface locale ignored browser preference.'
         )
 
     def test_stats(self):
diff --git a/tests/unit/test_webutils.py b/tests/unit/test_webutils.py
index 6da39a071..8bb3a0447 100644
--- a/tests/unit/test_webutils.py
+++ b/tests/unit/test_webutils.py
@@ -5,12 +5,13 @@ from tests import SearxTestCase
 
 
 class TestWebUtils(SearxTestCase):
-
     def test_prettify_url(self):
-        data = (('https://searx.me/', 'https://searx.me/'),
-                ('https://searx.me/ű', 'https://searx.me/ű'),
-                ('https://searx.me/' + (100 * 'a'), 'https://searx.me/[...]aaaaaaaaaaaaaaaaa'),
-                ('https://searx.me/' + (100 * 'ű'), 'https://searx.me/[...]űűűűűűűűűűűűűűűűű'))
+        data = (
+            ('https://searx.me/', 'https://searx.me/'),
+            ('https://searx.me/ű', 'https://searx.me/ű'),
+            ('https://searx.me/' + (100 * 'a'), 'https://searx.me/[...]aaaaaaaaaaaaaaaaa'),
+            ('https://searx.me/' + (100 * 'ű'), 'https://searx.me/[...]űűűűűűűűűűűűűűűűű'),
+        )
 
         for test_url, expected in data:
             self.assertEqual(webutils.prettify_url(test_url, max_length=32), expected)
@@ -21,10 +22,7 @@ class TestWebUtils(SearxTestCase):
         self.assertEqual(webutils.highlight_content('', None), None)
         self.assertEqual(webutils.highlight_content(False, None), None)
 
-        contents = [
-            '<html></html>'
-            'not<'
-        ]
+        contents = ['<html></html>' 'not<']
         for content in contents:
             self.assertEqual(webutils.highlight_content(content, None), content)
 
@@ -35,30 +33,35 @@ class TestWebUtils(SearxTestCase):
         self.assertEqual(webutils.highlight_content(content, query), content)
 
         data = (
-            ('" test "',
-             'a test string',
-             'a <span class="highlight">test</span> string'),
-            ('"a"',
-             'this is a test string',
-             'this is<span class="highlight"> a </span>test string'),
-            ('a test',
-             'this is a test string that matches entire query',
-             'this is <span class="highlight">a test</span> string that matches entire query'),
-            ('this a test',
-             'this is a string to test.',
-             ('<span class="highlight">this</span> is<span class="highlight"> a </span>'
-              'string to <span class="highlight">test</span>.')),
-            ('match this "exact phrase"',
-             'this string contains the exact phrase we want to match',
-             ('<span class="highlight">this</span> string contains the <span class="highlight">exact</span>'
-              ' <span class="highlight">phrase</span> we want to <span class="highlight">match</span>'))
+            ('" test "', 'a test string', 'a <span class="highlight">test</span> string'),
+            ('"a"', 'this is a test string', 'this is<span class="highlight"> a </span>test string'),
+            (
+                'a test',
+                'this is a test string that matches entire query',
+                'this is <span class="highlight">a test</span> string that matches entire query',
+            ),
+            (
+                'this a test',
+                'this is a string to test.',
+                (
+                    '<span class="highlight">this</span> is<span class="highlight"> a </span>'
+                    'string to <span class="highlight">test</span>.'
+                ),
+            ),
+            (
+                'match this "exact phrase"',
+                'this string contains the exact phrase we want to match',
+                (
+                    '<span class="highlight">this</span> string contains the <span class="highlight">exact</span>'
+                    ' <span class="highlight">phrase</span> we want to <span class="highlight">match</span>'
+                ),
+            ),
         )
         for query, content, expected in data:
             self.assertEqual(webutils.highlight_content(content, query), expected)
 
 
 class TestUnicodeWriter(SearxTestCase):
-
     def setUp(self):
         self.unicode_writer = webutils.UnicodeWriter(mock.MagicMock())
 
@@ -74,7 +77,6 @@ class TestUnicodeWriter(SearxTestCase):
 
 
 class TestNewHmac(SearxTestCase):
-
     def test_bytes(self):
         for secret_key in ['secret', b'secret', 1]:
             if secret_key == 1:
@@ -82,6 +84,4 @@ class TestNewHmac(SearxTestCase):
                     webutils.new_hmac(secret_key, b'http://example.com')
                 continue
             res = webutils.new_hmac(secret_key, b'http://example.com')
-            self.assertEqual(
-                res,
-                '23e2baa2404012a5cc8e4a18b4aabf0dde4cb9b56f679ddc0fd6d7c24339d819')
+            self.assertEqual(res, '23e2baa2404012a5cc8e4a18b4aabf0dde4cb9b56f679ddc0fd6d7c24339d819')