Ponysearch/searx/engines/wolframalpha_api.py
2016-02-28 01:04:29 -06:00

122 lines
3.9 KiB
Python

# Wolfram Alpha (Science)
#
# @website https://www.wolframalpha.com
# @provide-api yes (https://api.wolframalpha.com/v2/)
#
# @using-api yes
# @results XML
# @stable yes
# @parse url, infobox
from urllib import urlencode
from lxml import etree
# 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"]'
answer_xpath = '//pod[attribute::primary="true"]/subpod/plaintext'
input_xpath = '//pod[starts-with(attribute::id, "Input")]/subpod/plaintext'
pods_xpath = '//pod'
subpods_xpath = './subpod'
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 = {u'\uf522': u'\u2192', # rigth arrow
u'\uf7b1': u'\u2115', # set of natural numbers
u'\uf7b4': u'\u211a', # set of rational numbers
u'\uf7b5': u'\u211d', # set of real numbers
u'\uf7bd': u'\u2124', # set of integer numbers
u'\uf74c': 'd', # differential
u'\uf74d': u'\u212f', # euler's number
u'\uf74e': 'i', # imaginary number
u'\uf7d9': '='} # equals sign
for k, v in pua_chars.iteritems():
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:
infobox_title = None
pods = search_results.xpath(pods_xpath)
result_chunks = []
for pod in pods:
pod_id = pod.xpath(pod_id_xpath)[0]
pod_title = pod.xpath(pod_title_xpath)[0]
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 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 []
# append infobox
results.append({'infobox': infobox_title,
'attributes': result_chunks,
'urls': [{'title': 'Wolfram|Alpha', 'url': resp.request.headers['Referer'].decode('utf8')}]})
# append link to site
results.append({'url': resp.request.headers['Referer'].decode('utf8'),
'title': 'Wolfram|Alpha',
'content': infobox_title})
return results