searxng/searx/engines/wikipedia.py

138 lines
3.7 KiB
Python

"""
Wikipedia (Web)
@website https://{language}.wikipedia.org
@provide-api yes
@using-api yes
@results JSON
@stable yes
@parse url, infobox
"""
from json import loads
from urllib import urlencode, quote
from lxml.html import fromstring
# search-url
base_url = 'https://{language}.wikipedia.org/'
search_postfix = 'w/api.php?'\
'action=query'\
'&format=json'\
'&{query}'\
'&prop=extracts|pageimages'\
'&exintro'\
'&explaintext'\
'&pithumbsize=300'\
'&redirects'
supported_languages_url = 'https://meta.wikimedia.org/wiki/List_of_Wikipedias'
# set language in base_url
def url_lang(lang):
lang = lang.split('-')[0]
if lang == 'all' or lang not in supported_languages:
language = 'en'
else:
language = lang
return base_url.format(language=language)
# do search-request
def request(query, params):
if query.islower():
query += '|' + query.title()
params['url'] = url_lang(params['language']) \
+ search_postfix.format(query=urlencode({'titles': query}))
return params
# get first meaningful paragraph
# this should filter out disambiguation pages and notes above first paragraph
# "magic numbers" were obtained by fine tuning
def extract_first_paragraph(content, title, image):
first_paragraph = None
failed_attempts = 0
for paragraph in content.split('\n'):
starts_with_title = paragraph.lower().find(title.lower(), 0, len(title) + 35)
length = len(paragraph)
if length >= 200 or (starts_with_title >= 0 and (image or length >= 150)):
first_paragraph = paragraph
break
failed_attempts += 1
if failed_attempts > 3:
return None
return first_paragraph
# get response from search-request
def response(resp):
results = []
search_result = loads(resp.content)
# wikipedia article's unique id
# first valid id is assumed to be the requested article
for article_id in search_result['query']['pages']:
page = search_result['query']['pages'][article_id]
if int(article_id) > 0:
break
if int(article_id) < 0:
return []
title = page.get('title')
image = page.get('thumbnail')
if image:
image = image.get('source')
extract = page.get('extract')
summary = extract_first_paragraph(extract, title, image)
if not summary:
return []
# link to wikipedia article
wikipedia_link = url_lang(resp.search_params['language']) \
+ 'wiki/' + quote(title.replace(' ', '_').encode('utf8'))
results.append({'url': wikipedia_link, 'title': title})
results.append({'infobox': title,
'id': wikipedia_link,
'content': summary,
'img_src': image,
'urls': [{'title': 'Wikipedia', 'url': wikipedia_link}]})
return results
# get supported languages from their site
def _fetch_supported_languages(resp):
supported_languages = {}
dom = fromstring(resp.text)
tables = dom.xpath('//table[contains(@class,"sortable")]')
for table in tables:
# exclude header row
trs = table.xpath('.//tr')[1:]
for tr in trs:
td = tr.xpath('./td')
code = td[3].xpath('./a')[0].text
name = td[2].xpath('./a')[0].text
english_name = td[1].xpath('./a')[0].text
articles = int(td[4].xpath('./a/b')[0].text.replace(',', ''))
# exclude languages with too few articles
if articles >= 100000:
supported_languages[code] = {"name": name, "english_name": english_name, "articles": articles}
return supported_languages