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searxng/searx/engines/bing.py
Markus Heiser e0a6ca96cc [doc] add a description of bing engines (web, news, video, images)
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
2023-03-24 10:37:42 +01:00

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# SPDX-License-Identifier: AGPL-3.0-or-later
# lint: pylint
"""This is the implementation of the Bing-WEB engine. Some of this
implementations are shared by other engines:
- :ref:`bing images engine`
- :ref:`bing news engine`
- :ref:`bing videos engine`
On the `preference page`_ Bing offers a lot of languages an regions (see section
'Search results languages' and 'Country/region'). However, the abundant choice
does not correspond to reality, where Bing has a full-text indexer only for a
limited number of languages. By example: you can select a language like Māori
but you never get a result in this language.
What comes a bit closer to the truth are the `search-APIs`_ but they don`t seem
to be completely correct either (if you take a closer look you will find some
inaccuracies there too):
- :py:obj:`searx.engines.bing.bing_traits_url`
- :py:obj:`searx.engines.bing_videos.bing_traits_url`
- :py:obj:`searx.engines.bing_images.bing_traits_url`
- :py:obj:`searx.engines.bing_news.bing_traits_url`
.. _preference page: https://www.bing.com/account/general
.. _search-APIs: https://learn.microsoft.com/en-us/bing/search-apis/
"""
# pylint: disable=too-many-branches, invalid-name
from typing import TYPE_CHECKING
import datetime
import re
import uuid
from urllib.parse import urlencode
from lxml import html
import babel
import babel.languages
from searx.utils import eval_xpath, extract_text, eval_xpath_list, eval_xpath_getindex
from searx import network
from searx.locales import language_tag, region_tag
from searx.enginelib.traits import EngineTraits
if TYPE_CHECKING:
import logging
logger: logging.Logger
traits: EngineTraits
about = {
"website": 'https://www.bing.com',
"wikidata_id": 'Q182496',
"official_api_documentation": 'https://www.microsoft.com/en-us/bing/apis/bing-web-search-api',
"use_official_api": False,
"require_api_key": False,
"results": 'HTML',
}
send_accept_language_header = True
"""Bing tries to guess user's language and territory from the HTTP
Accept-Language. Optional the user can select a search-language (can be
different to the UI language) and a region (market code)."""
# engine dependent config
categories = ['general', 'web']
paging = True
time_range_support = True
safesearch = True
safesearch_types = {2: 'STRICT', 1: 'DEMOTE', 0: 'OFF'} # cookie: ADLT=STRICT
base_url = 'https://www.bing.com/search'
"""Bing (Web) search URL"""
bing_traits_url = 'https://learn.microsoft.com/en-us/bing/search-apis/bing-web-search/reference/market-codes'
"""Bing (Web) search API description"""
def _get_offset_from_pageno(pageno):
return (pageno - 1) * 10 + 1
def set_bing_cookies(params, engine_language, engine_region, SID):
# set cookies
# -----------
params['cookies']['_EDGE_V'] = '1'
# _EDGE_S: F=1&SID=3A5253BD6BCA609509B741876AF961CA&mkt=zh-tw
_EDGE_S = [
'F=1',
'SID=%s' % SID,
'mkt=%s' % engine_region.lower(),
'ui=%s' % engine_language.lower(),
]
params['cookies']['_EDGE_S'] = '&'.join(_EDGE_S)
logger.debug("cookie _EDGE_S=%s", params['cookies']['_EDGE_S'])
# "_EDGE_CD": "m=zh-tw",
_EDGE_CD = [ # pylint: disable=invalid-name
'm=%s' % engine_region.lower(), # search region: zh-cn
'u=%s' % engine_language.lower(), # UI: en-us
]
params['cookies']['_EDGE_CD'] = '&'.join(_EDGE_CD) + ';'
logger.debug("cookie _EDGE_CD=%s", params['cookies']['_EDGE_CD'])
SRCHHPGUSR = [ # pylint: disable=invalid-name
'SRCHLANG=%s' % engine_language,
# Trying to set ADLT cookie here seems not to have any effect, I assume
# there is some age verification by a cookie (and/or session ID) needed,
# to disable the SafeSearch.
'ADLT=%s' % safesearch_types.get(params['safesearch'], 'DEMOTE'),
]
params['cookies']['SRCHHPGUSR'] = '&'.join(SRCHHPGUSR)
logger.debug("cookie SRCHHPGUSR=%s", params['cookies']['SRCHHPGUSR'])
def request(query, params):
"""Assemble a Bing-Web request."""
engine_region = traits.get_region(params['searxng_locale'], 'en-US')
engine_language = traits.get_language(params['searxng_locale'], 'en')
SID = uuid.uuid1().hex.upper()
CVID = uuid.uuid1().hex.upper()
set_bing_cookies(params, engine_language, engine_region, SID)
# build URL query
# ---------------
# query term
page = int(params.get('pageno', 1))
query_params = {
# fmt: off
'q': query,
'pq': query,
'cvid': CVID,
'qs': 'n',
'sp': '-1'
# fmt: on
}
# page
if page > 1:
referer = base_url + '?' + urlencode(query_params)
params['headers']['Referer'] = referer
logger.debug("headers.Referer --> %s", referer)
query_params['first'] = _get_offset_from_pageno(page)
if page == 2:
query_params['FORM'] = 'PERE'
elif page > 2:
query_params['FORM'] = 'PERE%s' % (page - 2)
filters = ''
if params['time_range']:
query_params['filt'] = 'custom'
if params['time_range'] == 'day':
filters = 'ex1:"ez1"'
elif params['time_range'] == 'week':
filters = 'ex1:"ez2"'
elif params['time_range'] == 'month':
filters = 'ex1:"ez3"'
elif params['time_range'] == 'year':
epoch_1970 = datetime.date(1970, 1, 1)
today_no = (datetime.date.today() - epoch_1970).days
filters = 'ex1:"ez5_%s_%s"' % (today_no - 365, today_no)
params['url'] = base_url + '?' + urlencode(query_params)
if filters:
params['url'] = params['url'] + '&filters=' + filters
return params
def response(resp):
results = []
result_len = 0
dom = html.fromstring(resp.text)
# parse results again if nothing is found yet
url_to_resolve = []
url_to_resolve_index = []
i = 0
for result in eval_xpath_list(dom, '//ol[@id="b_results"]/li[contains(@class, "b_algo")]'):
link = eval_xpath_getindex(result, './/h2/a', 0, None)
if link is None:
continue
url = link.attrib.get('href')
title = extract_text(link)
# Make sure that the element is free of <a href> links and <span class='algoSlug_icon'>
content = eval_xpath(result, '(.//p)[1]')
for p in content:
for e in p.xpath('.//a'):
e.getparent().remove(e)
for e in p.xpath('.//span[@class="algoSlug_icon"]'):
e.getparent().remove(e)
content = extract_text(content)
# get the real URL either using the URL shown to user or following the Bing URL
if url.startswith('https://www.bing.com/ck/a?'):
url_cite = extract_text(eval_xpath(result, './/div[@class="b_attribution"]/cite'))
# Bing can shorten the URL either at the end or in the middle of the string
if (
url_cite
and url_cite.startswith('https://')
and '' not in url_cite
and '...' not in url_cite
and '' not in url_cite
):
# no need for an additional HTTP request
url = url_cite
else:
# resolve the URL with an additional HTTP request
url_to_resolve.append(url.replace('&ntb=1', '&ntb=F'))
url_to_resolve_index.append(i)
url = None # remove the result if the HTTP Bing redirect raise an exception
# append result
results.append({'url': url, 'title': title, 'content': content})
# increment result pointer for the next iteration in this loop
i += 1
# resolve all Bing redirections in parallel
request_list = [
network.Request.get(u, allow_redirects=False, headers=resp.search_params['headers']) for u in url_to_resolve
]
response_list = network.multi_requests(request_list)
for i, redirect_response in enumerate(response_list):
if not isinstance(redirect_response, Exception):
results[url_to_resolve_index[i]]['url'] = redirect_response.headers['location']
# get number_of_results
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 = re.sub('[^0-9]', '', result_len_container)
if len(result_len_container) > 0:
result_len = int(result_len_container)
except Exception as e: # pylint: disable=broad-except
logger.debug('result error :\n%s', e)
if result_len and _get_offset_from_pageno(resp.search_params.get("pageno", 0)) > result_len:
return []
results.append({'number_of_results': result_len})
return results
def fetch_traits(engine_traits: EngineTraits):
"""Fetch languages and regions from Bing-Web."""
xpath_market_codes = '//table[1]/tbody/tr/td[3]'
# xpath_country_codes = '//table[2]/tbody/tr/td[2]'
xpath_language_codes = '//table[3]/tbody/tr/td[2]'
_fetch_traits(engine_traits, bing_traits_url, xpath_language_codes, xpath_market_codes)
def _fetch_traits(engine_traits: EngineTraits, url: str, xpath_language_codes: str, xpath_market_codes: str):
# insert alias to map from a language (zh) to a language + script (zh_Hans)
engine_traits.languages['zh'] = 'zh-hans'
resp = network.get(url)
if not resp.ok:
print("ERROR: response from peertube is not OK.")
dom = html.fromstring(resp.text)
map_lang = {'jp': 'ja'}
for td in eval_xpath(dom, xpath_language_codes):
eng_lang = td.text
if eng_lang in ('en-gb', 'pt-br'):
# language 'en' is already in the list and a language 'en-gb' can't
# be handled in SearXNG, same with pt-br which is covered by pt-pt.
continue
babel_lang = map_lang.get(eng_lang, eng_lang).replace('-', '_')
try:
sxng_tag = language_tag(babel.Locale.parse(babel_lang))
except babel.UnknownLocaleError:
print("ERROR: language (%s) is unknown by babel" % (eng_lang))
continue
conflict = engine_traits.languages.get(sxng_tag)
if conflict:
if conflict != eng_lang:
print("CONFLICT: babel %s --> %s, %s" % (sxng_tag, conflict, eng_lang))
continue
engine_traits.languages[sxng_tag] = eng_lang
map_region = {
'en-ID': 'id_ID',
'no-NO': 'nb_NO',
}
for td in eval_xpath(dom, xpath_market_codes):
eng_region = td.text
babel_region = map_region.get(eng_region, eng_region).replace('-', '_')
if eng_region == 'en-WW':
engine_traits.all_locale = eng_region
continue
try:
sxng_tag = region_tag(babel.Locale.parse(babel_region))
except babel.UnknownLocaleError:
print("ERROR: region (%s) is unknown by babel" % (eng_region))
continue
conflict = engine_traits.regions.get(sxng_tag)
if conflict:
if conflict != eng_region:
print("CONFLICT: babel %s --> %s, %s" % (sxng_tag, conflict, eng_region))
continue
engine_traits.regions[sxng_tag] = eng_region