searxng/searx/engines/google_scholar.py
2022-07-09 21:33:24 +00:00

150 lines
4.1 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-or-later
# lint: pylint
"""Google (Scholar)
For detailed description of the *REST-full* API see: `Query Parameter
Definitions`_.
.. _Query Parameter Definitions:
https://developers.google.com/custom-search/docs/xml_results#WebSearch_Query_Parameter_Definitions
"""
# pylint: disable=invalid-name
from urllib.parse import urlencode
from datetime import datetime
from lxml import html
from searx.utils import (
eval_xpath,
eval_xpath_list,
extract_text,
)
from searx.engines.google import (
get_lang_info,
time_range_dict,
detect_google_sorry,
)
# pylint: disable=unused-import
from searx.engines.google import (
supported_languages_url,
_fetch_supported_languages,
)
# pylint: enable=unused-import
# about
about = {
"website": 'https://scholar.google.com',
"wikidata_id": 'Q494817',
"official_api_documentation": 'https://developers.google.com/custom-search',
"use_official_api": False,
"require_api_key": False,
"results": 'HTML',
}
# engine dependent config
categories = ['science']
paging = True
language_support = True
use_locale_domain = True
time_range_support = True
safesearch = False
def time_range_url(params):
"""Returns a URL query component for a google-Scholar time range based on
``params['time_range']``. Google-Scholar does only support ranges in years.
To have any effect, all the Searx ranges (*day*, *week*, *month*, *year*)
are mapped to *year*. If no range is set, an empty string is returned.
Example::
&as_ylo=2019
"""
# as_ylo=2016&as_yhi=2019
ret_val = ''
if params['time_range'] in time_range_dict:
ret_val = urlencode({'as_ylo': datetime.now().year - 1})
return '&' + ret_val
def request(query, params):
"""Google-Scholar search request"""
offset = (params['pageno'] - 1) * 10
lang_info = get_lang_info(params, supported_languages, language_aliases, False)
logger.debug("HTTP header Accept-Language --> %s", lang_info['headers']['Accept-Language'])
# subdomain is: scholar.google.xy
lang_info['subdomain'] = lang_info['subdomain'].replace("www.", "scholar.")
query_url = (
'https://'
+ lang_info['subdomain']
+ '/scholar'
+ "?"
+ urlencode({'q': query, **lang_info['params'], 'ie': "utf8", 'oe': "utf8", 'start': offset, 'ucbcb': 1})
)
query_url += time_range_url(params)
params['url'] = query_url
params['headers'].update(lang_info['headers'])
params['headers']['Accept'] = 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'
# params['google_subdomain'] = subdomain
return params
def response(resp):
"""Get response from google's search request"""
results = []
detect_google_sorry(resp)
# which subdomain ?
# subdomain = resp.search_params.get('google_subdomain')
# convert the text to dom
dom = html.fromstring(resp.text)
# parse results
for result in eval_xpath_list(dom, '//div[@class="gs_ri"]'):
title = extract_text(eval_xpath(result, './h3[1]//a'))
if not title:
# this is a [ZITATION] block
continue
url = eval_xpath(result, './h3[1]//a/@href')[0]
content = extract_text(eval_xpath(result, './div[@class="gs_rs"]')) or ''
pub_info = extract_text(eval_xpath(result, './div[@class="gs_a"]'))
if pub_info:
content += "[%s]" % pub_info
pub_type = extract_text(eval_xpath(result, './/span[@class="gs_ct1"]'))
if pub_type:
title = title + " " + pub_type
results.append(
{
'url': url,
'title': title,
'content': content,
}
)
# parse suggestion
for suggestion in eval_xpath(dom, '//div[contains(@class, "gs_qsuggest_wrap")]//li//a'):
# append suggestion
results.append({'suggestion': extract_text(suggestion)})
for correction in eval_xpath(dom, '//div[@class="gs_r gs_pda"]/a'):
results.append({'correction': extract_text(correction)})
return results