summaryrefslogtreecommitdiff
path: root/searx/engines/wolframalpha_api.py
blob: 5670e356fcfd23fc7a0bd8a93016400980e11882 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
# SPDX-License-Identifier: AGPL-3.0-or-later
"""Wolfram|Alpha (Science)

"""

from urllib.parse import urlencode

from lxml import etree

# about
about = {
    "website": 'https://www.wolframalpha.com',
    "wikidata_id": 'Q207006',
    "official_api_documentation": 'https://products.wolframalpha.com/api/',
    "use_official_api": True,
    "require_api_key": False,
    "results": 'XML',
}

# search-url
search_url = 'https://api.wolframalpha.com/v2/query?appid={api_key}&{query}'
site_url = 'https://www.wolframalpha.com/input/?{query}'
api_key = ''  # defined in settings.yml

# xpath variables
failure_xpath = '/queryresult[attribute::success="false"]'
input_xpath = '//pod[starts-with(attribute::id, "Input")]/subpod/plaintext'
pods_xpath = '//pod'
subpods_xpath = './subpod'
pod_primary_xpath = './@primary'
pod_id_xpath = './@id'
pod_title_xpath = './@title'
plaintext_xpath = './plaintext'
image_xpath = './img'
img_src_xpath = './@src'
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'}


# do search-request
def request(query, params):
    params['url'] = search_url.format(query=urlencode({'input': query}), api_key=api_key)
    params['headers']['Referer'] = site_url.format(query=urlencode({'i': query}))

    return params


# replace private user area characters to make text legible
def replace_pua_chars(text):
    pua_chars = {
        '\uf522': '\u2192',  # right 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)

    return text


# get response from search-request
def response(resp):
    results = []

    search_results = etree.XML(resp.content)

    # return empty array if there are no results
    if search_results.xpath(failure_xpath):
        return []

    try:
        infobox_title = search_results.xpath(input_xpath)[0].text
    except:  # pylint: disable=bare-except
        infobox_title = ""

    pods = search_results.xpath(pods_xpath)
    result_chunks = []
    result_content = ""
    for pod in pods:
        pod_id = pod.xpath(pod_id_xpath)[0]
        pod_title = pod.xpath(pod_title_xpath)[0]
        pod_is_result = pod.xpath(pod_primary_xpath)

        subpods = pod.xpath(subpods_xpath)
        if not subpods:
            continue

        # Appends either a text or an image, depending on which one is more suitable
        for subpod in subpods:
            content = subpod.xpath(plaintext_xpath)[0].text
            image = subpod.xpath(image_xpath)

            if content and pod_id not in image_pods:

                if pod_is_result or not result_content:
                    if pod_id != "Input":
                        result_content = "%s: %s" % (pod_title, content)

                # if no input pod was found, title is first plaintext pod
                if not infobox_title:
                    infobox_title = content

                content = replace_pua_chars(content)
                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]},
                    }
                )

    if not result_chunks:
        return []

    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']}],
        }
    )

    # append link to site
    results.append({'url': resp.request.headers['Referer'], 'title': title, 'content': result_content})

    return results