searxng/searx/engines/duckduckgo.py
Markus Heiser 4c9b8b29ee [mod] engine duckduckgo - use DuckDuckGo-Lite
Implement a scrapper for DuckDuckGo-Lite [1].  The existing DuckDuckGo [2]
engine does not support paging.  DuckDuckgo-Lite is much faster, less verbose
and does have a paging option (reversed engineered from the input form of [1]).

[1] https://lite.duckduckgo.com/lite
[2] https://duckduckgo.com/

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
2021-10-01 20:01:41 +02:00

186 lines
5.2 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-or-later
# lint: pylint
"""DuckDuckGo Lite
"""
from json import loads
from lxml.html import fromstring
from searx.utils import (
dict_subset,
eval_xpath,
eval_xpath_getindex,
extract_text,
match_language,
)
from searx.network import get
# about
about = {
"website": 'https://lite.duckduckgo.com/lite',
"wikidata_id": 'Q12805',
"official_api_documentation": 'https://duckduckgo.com/api',
"use_official_api": False,
"require_api_key": False,
"results": 'HTML',
}
# engine dependent config
categories = ['general']
paging = True
supported_languages_url = 'https://duckduckgo.com/util/u172.js'
time_range_support = True
language_aliases = {
'ar-SA': 'ar-XA',
'es-419': 'es-XL',
'ja': 'jp-JP',
'ko': 'kr-KR',
'sl-SI': 'sl-SL',
'zh-TW': 'tzh-TW',
'zh-HK': 'tzh-HK'
}
time_range_dict = {
'day': 'd',
'week': 'w',
'month': 'm',
'year': 'y'
}
# search-url
url = 'https://lite.duckduckgo.com/lite'
url_ping = 'https://duckduckgo.com/t/sl_l'
# match query's language to a region code that duckduckgo will accept
def get_region_code(lang, lang_list=None):
if lang == 'all':
return None
lang_code = match_language(lang, lang_list or [], language_aliases, 'wt-WT')
lang_parts = lang_code.split('-')
# country code goes first
return lang_parts[1].lower() + '-' + lang_parts[0].lower()
def request(query, params):
params['url'] = url
params['method'] = 'POST'
params['data']['q'] = query
# The API is not documented, so we do some reverse engineering and emulate
# what https://lite.duckduckgo.com/lite/ does when you press "next Page"
# link again and again ..
params['headers']['Content-Type'] = 'application/x-www-form-urlencoded'
# initial page does not have an offset
if params['pageno'] == 2:
# second page does have an offset of 30
offset = (params['pageno'] - 1) * 30
params['data']['s'] = offset
params['data']['dc'] = offset + 1
elif params['pageno'] > 2:
# third and following pages do have an offset of 30 + n*50
offset = 30 + (params['pageno'] - 2) * 50
params['data']['s'] = offset
params['data']['dc'] = offset + 1
# initial page does not have additional data in the input form
if params['pageno'] > 1:
# request the second page (and more pages) needs 'o' and 'api' arguments
params['data']['o'] = 'json'
params['data']['api'] = 'd.js'
# initial page does not have additional data in the input form
if params['pageno'] > 2:
# request the third page (and more pages) some more arguments
params['data']['nextParams'] = ''
params['data']['v'] = ''
params['data']['vqd'] = ''
region_code = get_region_code(params['language'], supported_languages)
if region_code:
params['data']['kl'] = region_code
params['cookies']['kl'] = region_code
params['data']['df'] = ''
if params['time_range'] in time_range_dict:
params['data']['df'] = time_range_dict[params['time_range']]
params['cookies']['df'] = time_range_dict[params['time_range']]
logger.debug("param data: %s", params['data'])
logger.debug("param cookies: %s", params['cookies'])
return params
# get response from search-request
def response(resp):
headers_ping = dict_subset(resp.request.headers, ['User-Agent', 'Accept-Encoding', 'Accept', 'Cookie'])
get(url_ping, headers=headers_ping)
if resp.status_code == 303:
return []
results = []
doc = fromstring(resp.text)
result_table = eval_xpath(doc, '//html/body/form/div[@class="filters"]/table')
if not len(result_table) >= 3:
# no more results
return []
result_table = result_table[2]
tr_rows = eval_xpath(result_table, './/tr')
# In the last <tr> is the form of the 'previous/next page' links
tr_rows = tr_rows[:-1]
len_tr_rows = len(tr_rows)
offset = 0
while len_tr_rows >= offset + 4:
# assemble table rows we need to scrap
tr_title = tr_rows[offset]
tr_content = tr_rows[offset + 1]
offset += 4
# ignore sponsored Adds <tr class="result-sponsored">
if tr_content.get('class') == 'result-sponsored':
continue
a_tag = eval_xpath_getindex(tr_title, './/td//a[@class="result-link"]', 0, None)
if a_tag is None:
continue
td_content = eval_xpath_getindex(tr_content, './/td[@class="result-snippet"]', 0, None)
if td_content is None:
continue
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]
regions_json = loads(response_page)
supported_languages = map((lambda x: x[3:] + '-' + x[:2].upper()), regions_json.keys())
return list(supported_languages)