[mod] DuckDuckGo: reversed engineered & upgrade to data_type: traits_v1

Partial reverse engineering of the DuckDuckGo (DDG) engines including a
improved language and region handling based on the enigne.traits_v1 data.

- DDG Lite
- DDG Instant Answer API
- DDG Images
- DDG Weather

docs/src/searx.engine.duckduckgo.rst:
  Online documentation of the DDG engines (make docs.live)

searx/data/engine_traits.json
  Add data type "traits_v1" generated by the fetch_traits() functions from:

  - "duckduckgo" (WEB),
  - "duckduckgo images" and
  - "duckduckgo weather"

  and remove data from obsolete data type "supported_languages".

searx/autocomplete.py:
  Reversed engineered Autocomplete from DDG.  Supports DDG's languages.

searx/engines/duckduckgo.py:
  - fetch_traits():  Fetch languages & regions from DDG.

  - get_ddg_lang(): Get DDG's language identifier from SearXNG's locale.  DDG
    defines its languages by region codes.  DDG-Lite does not offer a language
    selection to the user, only a region can be selected by the user.

  - Cache ``vqd`` value: The vqd value depends on the query string and is needed
    for the follow up pages or the images loaded by a XMLHttpRequest (DDG
    images).  The ``vqd`` value of a search term is stored for 10min in the
    redis DB.

  - DDG Lite engine: reversed engineered request method with improved Language
    and region support and better ``vqd`` handling.

searx/engines/duckduckgo_definitions.py: DDG Instant Answer API
  The *instant answers* API does not support languages, or at least we could not
  find out how language support should work.  It seems that most of the features
  are based on English terms.

searx/engines/duckduckgo_images.py: DDG Images
  Reversed engineered request method.  Improved language and region handling
  based on cookies and the enigne.traits_v1 data.  Response: add image format to
  the result list

searx/engines/duckduckgo_weather.py: DDG Weather
  Improved language and region handling based on cookies and the
  enigne.traits_v1 data.

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
This commit is contained in:
Markus Heiser 2022-11-05 15:10:52 +01:00
parent e9afc4f8ce
commit c80e82a855
8 changed files with 775 additions and 442 deletions

View file

@ -1,73 +1,207 @@
# SPDX-License-Identifier: AGPL-3.0-or-later
# lint: pylint
"""DuckDuckGo Lite
"""
DuckDuckGo Lite
~~~~~~~~~~~~~~~
"""
from typing import TYPE_CHECKING
from urllib.parse import urlencode
import json
from lxml import html
import babel
import lxml.html
from searx import (
network,
locales,
redislib,
)
from searx import redisdb
from searx.utils import (
dict_subset,
eval_xpath,
eval_xpath_getindex,
extract_text,
match_language,
)
from searx import network
from searx.enginelib.traits import EngineTraits
from searx.exceptions import SearxEngineAPIException
if TYPE_CHECKING:
import logging
logger: logging.Logger
traits: EngineTraits
# 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',
}
send_accept_language_header = True
"""DuckDuckGo-Lite tries to guess user's prefered language from the HTTP
``Accept-Language``. Optional the user can select a region filter (but not a
language).
"""
# engine dependent config
categories = ['general', 'web']
paging = True
supported_languages_url = 'https://duckduckgo.com/util/u588.js'
time_range_support = True
send_accept_language_header = True
safesearch = True # user can't select but the results are filtered
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',
}
url = 'https://lite.duckduckgo.com/lite/'
# url_ping = 'https://duckduckgo.com/t/sl_l'
time_range_dict = {'day': 'd', 'week': 'w', 'month': 'm', 'year': 'y'}
form_data = {'v': 'l', 'api': 'd.js', 'o': 'json'}
# 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
def cache_vqd(query, value):
"""Caches a ``vqd`` value from a query.
lang_code = match_language(lang, lang_list or [], language_aliases, 'wt-WT')
lang_parts = lang_code.split('-')
The vqd value depends on the query string and is needed for the follow up
pages or the images loaded by a XMLHttpRequest:
# country code goes first
return lang_parts[1].lower() + '-' + lang_parts[0].lower()
- DuckDuckGo Web: `https://links.duckduckgo.com/d.js?q=...&vqd=...`
- DuckDuckGo Images: `https://duckduckgo.com/i.js??q=...&vqd=...`
"""
c = redisdb.client()
if c:
logger.debug("cache vqd value: %s", value)
key = 'SearXNG_ddg_vqd' + redislib.secret_hash(query)
c.set(key, value, ex=600)
def get_vqd(query, headers):
"""Returns the ``vqd`` that fits to the *query*. If there is no ``vqd`` cached
(:py:obj:`cache_vqd`) the query is sent to DDG to get a vqd value from the
response.
"""
value = None
c = redisdb.client()
if c:
key = 'SearXNG_ddg_vqd' + redislib.secret_hash(query)
value = c.get(key)
if value:
value = value.decode('utf-8')
logger.debug("re-use cached vqd value: %s", value)
return value
query_url = 'https://duckduckgo.com/?{query}&iar=images'.format(query=urlencode({'q': query}))
res = network.get(query_url, headers=headers)
content = res.text
if content.find('vqd=\'') == -1:
raise SearxEngineAPIException('Request failed')
value = content[content.find('vqd=\'') + 5 :]
value = value[: value.find('\'')]
logger.debug("new vqd value: %s", value)
cache_vqd(query, value)
return value
def get_ddg_lang(eng_traits: EngineTraits, sxng_locale, default='en_US'):
"""Get DuckDuckGo's language identifier from SearXNG's locale.
DuckDuckGo defines its lanaguages by region codes (see
:py:obj:`fetch_traits`).
To get region and language of a DDG service use:
.. code: python
eng_region = traits.get_region(params['searxng_locale'], traits.all_locale)
eng_lang = get_ddg_lang(traits, params['searxng_locale'])
It might confuse, but the ``l`` value of the cookie is what SearXNG calls
the *region*:
.. code:: python
# !ddi paris :es-AR --> {'ad': 'es_AR', 'ah': 'ar-es', 'l': 'ar-es'}
params['cookies']['ad'] = eng_lang
params['cookies']['ah'] = eng_region
params['cookies']['l'] = eng_region
.. hint::
`DDG-lite <https://lite.duckduckgo.com/lite>`__ does not offer a language
selection to the user, only a region can be selected by the user
(``eng_region`` from the example above). DDG-lite stores the selected
region in a cookie::
params['cookies']['kl'] = eng_region # 'ar-es'
"""
return eng_traits.custom['lang_region'].get(sxng_locale, eng_traits.get_language(sxng_locale, default))
ddg_reg_map = {
'tw-tzh': 'zh_TW',
'hk-tzh': 'zh_HK',
'ct-ca': 'skip', # ct-ca and es-ca both map to ca_ES
'es-ca': 'ca_ES',
'id-en': 'id_ID',
'no-no': 'nb_NO',
'jp-jp': 'ja_JP',
'kr-kr': 'ko_KR',
'xa-ar': 'ar_SA',
'sl-sl': 'sl_SI',
'th-en': 'th_TH',
'vn-en': 'vi_VN',
}
ddg_lang_map = {
# use ar --> ar_EG (Egypt's arabic)
"ar_DZ": 'lang_region',
"ar_JO": 'lang_region',
"ar_SA": 'lang_region',
# use bn --> bn_BD
'bn_IN': 'lang_region',
# use de --> de_DE
'de_CH': 'lang_region',
# use en --> en_US,
'en_AU': 'lang_region',
'en_CA': 'lang_region',
'en_GB': 'lang_region',
# Esperanto
'eo_XX': 'eo',
# use es --> es_ES,
'es_AR': 'lang_region',
'es_CL': 'lang_region',
'es_CO': 'lang_region',
'es_CR': 'lang_region',
'es_EC': 'lang_region',
'es_MX': 'lang_region',
'es_PE': 'lang_region',
'es_UY': 'lang_region',
'es_VE': 'lang_region',
# use fr --> rf_FR
'fr_CA': 'lang_region',
'fr_CH': 'lang_region',
'fr_BE': 'lang_region',
# use nl --> nl_NL
'nl_BE': 'lang_region',
# use pt --> pt_PT
'pt_BR': 'lang_region',
# skip these languages
'od_IN': 'skip',
'io_XX': 'skip',
'tokipona_XX': 'skip',
}
def request(query, params):
eng_region = traits.get_region(params['searxng_locale'], traits.all_locale)
# eng_lang = get_ddg_lang(traits, params['searxng_locale'])
params['url'] = url
params['method'] = 'POST'
params['data']['q'] = query
# The API is not documented, so we do some reverse engineering and emulate
@ -90,23 +224,19 @@ def request(query, params):
params['data']['s'] = offset
params['data']['dc'] = offset + 1
# request needs a vqd argument
params['data']['vqd'] = get_vqd(query, params["headers"])
# 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'] = ''
params['data']['o'] = form_data.get('o', 'json')
params['data']['api'] = form_data.get('api', 'd.js')
params['data']['nextParams'] = form_data.get('nextParams', '')
params['data']['v'] = form_data.get('v', 'l')
region_code = get_region_code(params['language'], supported_languages)
if region_code:
params['data']['kl'] = region_code
params['cookies']['kl'] = region_code
params['data']['kl'] = eng_region
params['cookies']['kl'] = eng_region
params['data']['df'] = ''
if params['time_range'] in time_range_dict:
@ -118,26 +248,40 @@ def request(query, params):
return params
# get response from search-request
def response(resp):
headers_ping = dict_subset(resp.request.headers, ['User-Agent', 'Accept-Encoding', 'Accept', 'Cookie'])
network.get(url_ping, headers=headers_ping)
if resp.status_code == 303:
return []
results = []
doc = html.fromstring(resp.text)
doc = lxml.html.fromstring(resp.text)
result_table = eval_xpath(doc, '//html/body/form/div[@class="filters"]/table')
if not len(result_table) >= 3:
if len(result_table) == 2:
# some locales (at least China) does not have a "next page" button and
# the layout of the HTML tables is different.
result_table = result_table[1]
elif not len(result_table) >= 3:
# no more results
return []
result_table = result_table[2]
else:
result_table = result_table[2]
# update form data from response
form = eval_xpath(doc, '//html/body/form/div[@class="filters"]/table//input/..')
if len(form):
form = form[0]
form_data['v'] = eval_xpath(form, '//input[@name="v"]/@value')[0]
form_data['api'] = eval_xpath(form, '//input[@name="api"]/@value')[0]
form_data['o'] = eval_xpath(form, '//input[@name="o"]/@value')[0]
logger.debug('form_data: %s', form_data)
value = eval_xpath(form, '//input[@name="vqd"]/@value')[0]
query = resp.search_params['data']['q']
cache_vqd(query, value)
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]
@ -174,32 +318,35 @@ def response(resp):
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 = json.loads(response_page)
supported_languages = map((lambda x: x[3:] + '-' + x[:2].upper()), regions_json.keys())
return list(supported_languages)
def fetch_traits(engine_traits: EngineTraits):
"""Fetch regions from DuckDuckGo."""
# pylint: disable=import-outside-toplevel
"""Fetch languages & regions from DuckDuckGo.
engine_traits.data_type = 'supported_languages' # deprecated
SearXNG's ``all`` locale maps DuckDuckGo's "Alle regions" (``wt-wt``).
DuckDuckGo's language "Browsers prefered language" (``wt_WT``) makes no
sense in a SearXNG request since SearXNG's ``all`` will not add a
``Accept-Language`` HTTP header. The value in ``engine_traits.all_locale``
is ``wt-wt`` (the region).
import babel
from searx.locales import region_tag
Beside regions DuckDuckGo also defines its lanaguages by region codes. By
example these are the english languages in DuckDuckGo:
- en_US
- en_AU
- en_CA
- en_GB
The function :py:obj:`get_ddg_lang` evaluates DuckDuckGo's language from
SearXNG's locale.
"""
# pylint: disable=too-many-branches, too-many-statements
# fetch regions
engine_traits.all_locale = 'wt-wt'
resp = network.get('https://duckduckgo.com/util/u588.js')
# updated from u588 to u661 / should be updated automatically?
resp = network.get('https://duckduckgo.com/util/u661.js')
if not resp.ok:
print("ERROR: response from DuckDuckGo is not OK.")
@ -208,28 +355,13 @@ def fetch_traits(engine_traits: EngineTraits):
pos = js_code.find('}') + 1
regions = json.loads(js_code[:pos])
reg_map = {
'tw-tzh': 'zh_TW',
'hk-tzh': 'zh_HK',
'ct-ca': 'skip', # ct-ca and es-ca both map to ca_ES
'es-ca': 'ca_ES',
'id-en': 'id_ID',
'no-no': 'nb_NO',
'jp-jp': 'ja_JP',
'kr-kr': 'ko_KR',
'xa-ar': 'ar_SA',
'sl-sl': 'sl_SI',
'th-en': 'th_TH',
'vn-en': 'vi_VN',
}
for eng_tag, name in regions.items():
if eng_tag == 'wt-wt':
engine_traits.all_locale = 'wt-wt'
continue
region = reg_map.get(eng_tag)
region = ddg_reg_map.get(eng_tag)
if region == 'skip':
continue
@ -238,7 +370,7 @@ def fetch_traits(engine_traits: EngineTraits):
region = eng_lang + '_' + eng_territory.upper()
try:
sxng_tag = region_tag(babel.Locale.parse(region))
sxng_tag = locales.region_tag(babel.Locale.parse(region))
except babel.UnknownLocaleError:
print("ERROR: %s (%s) -> %s is unknown by babel" % (name, eng_tag, region))
continue
@ -249,3 +381,42 @@ def fetch_traits(engine_traits: EngineTraits):
print("CONFLICT: babel %s --> %s, %s" % (sxng_tag, conflict, eng_tag))
continue
engine_traits.regions[sxng_tag] = eng_tag
# fetch languages
engine_traits.custom['lang_region'] = {}
pos = resp.text.find('languages:{') + 10
js_code = resp.text[pos:]
pos = js_code.find('}') + 1
js_code = '{"' + js_code[1:pos].replace(':', '":').replace(',', ',"')
languages = json.loads(js_code)
for eng_lang, name in languages.items():
if eng_lang == 'wt_WT':
continue
babel_tag = ddg_lang_map.get(eng_lang, eng_lang)
if babel_tag == 'skip':
continue
try:
if babel_tag == 'lang_region':
sxng_tag = locales.region_tag(babel.Locale.parse(eng_lang))
engine_traits.custom['lang_region'][sxng_tag] = eng_lang
continue
sxng_tag = locales.language_tag(babel.Locale.parse(babel_tag))
except babel.UnknownLocaleError:
print("ERROR: language %s (%s) is unknown by babel" % (name, 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