searxng/searx/utils.py

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# -*- coding: utf-8 -*-
import sys
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import re
import importlib
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from numbers import Number
from os.path import splitext, join
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from random import choice
from html.parser import HTMLParser
from urllib.parse import urljoin, urlparse
from lxml import html
from lxml.etree import XPath, _ElementStringResult, _ElementUnicodeResult
from babel.core import get_global
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from searx import settings
from searx.data import USER_AGENTS
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from searx.version import VERSION_STRING
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from searx.languages import language_codes
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from searx import logger
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logger = logger.getChild('utils')
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blocked_tags = ('script',
'style')
ecma_unescape4_re = re.compile(r'%u([0-9a-fA-F]{4})', re.UNICODE)
ecma_unescape2_re = re.compile(r'%([0-9a-fA-F]{2})', re.UNICODE)
xpath_cache = dict()
lang_to_lc_cache = dict()
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def searx_useragent():
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"""Return the searx User Agent"""
return 'searx/{searx_version} {suffix}'.format(
searx_version=VERSION_STRING,
suffix=settings['outgoing'].get('useragent_suffix', ''))
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def gen_useragent(os=None):
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"""Return a random browser User Agent
See searx/data/useragents.json
"""
return str(USER_AGENTS['ua'].format(os=os or choice(USER_AGENTS['os']), version=choice(USER_AGENTS['versions'])))
class HTMLTextExtractorException(Exception):
pass
class HTMLTextExtractor(HTMLParser): # pylint: disable=W0223 # (see https://bugs.python.org/issue31844)
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def __init__(self):
HTMLParser.__init__(self)
self.result = []
self.tags = []
def handle_starttag(self, tag, attrs):
self.tags.append(tag)
def handle_endtag(self, tag):
if not self.tags:
return
if tag != self.tags[-1]:
raise HTMLTextExtractorException()
self.tags.pop()
def is_valid_tag(self):
return not self.tags or self.tags[-1] not in blocked_tags
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def handle_data(self, data):
if not self.is_valid_tag():
return
self.result.append(data)
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def handle_charref(self, name):
if not self.is_valid_tag():
return
if name[0] in ('x', 'X'):
codepoint = int(name[1:], 16)
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else:
codepoint = int(name)
self.result.append(chr(codepoint))
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def handle_entityref(self, name):
if not self.is_valid_tag():
return
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# codepoint = htmlentitydefs.name2codepoint[name]
# self.result.append(chr(codepoint))
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self.result.append(name)
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def get_text(self):
return ''.join(self.result).strip()
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def html_to_text(html_str):
"""Extract text from a HTML string
Args:
* html_str (str): string HTML
Returns:
* str: extracted text
Examples:
>>> html_to_text('Example <span id="42">#2</span>')
'Example #2'
>>> html_to_text('<style>.span { color: red; }</style><span>Example</span>')
'Example'
"""
html_str = html_str.replace('\n', ' ')
html_str = ' '.join(html_str.split())
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s = HTMLTextExtractor()
try:
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s.feed(html_str)
except HTMLTextExtractorException:
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logger.debug("HTMLTextExtractor: invalid HTML\n%s", html_str)
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return s.get_text()
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def extract_text(xpath_results):
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"""Extract text from a lxml result
* if xpath_results is list, extract the text from each result and concat the list
* if xpath_results is a xml element, extract all the text node from it
( text_content() method from lxml )
* if xpath_results is a string element, then it's already done
"""
if type(xpath_results) == list:
# it's list of result : concat everything using recursive call
result = ''
for e in xpath_results:
result = result + extract_text(e)
return result.strip()
elif type(xpath_results) in [_ElementStringResult, _ElementUnicodeResult]:
# it's a string
return ''.join(xpath_results)
else:
# it's a element
text = html.tostring(
xpath_results, encoding='unicode', method='text', with_tail=False
)
text = text.strip().replace('\n', ' ')
return ' '.join(text.split())
def normalize_url(url, base_url):
"""Normalize URL: add protocol, join URL with base_url, add trailing slash if there is no path
Args:
* url (str): Relative URL
* base_url (str): Base URL, it must be an absolute URL.
Example:
>>> normalize_url('https://example.com', 'http://example.com/')
'https://example.com/'
>>> normalize_url('//example.com', 'http://example.com/')
'http://example.com/'
>>> normalize_url('//example.com', 'https://example.com/')
'https://example.com/'
>>> normalize_url('/path?a=1', 'https://example.com')
'https://example.com/path?a=1'
>>> normalize_url('', 'https://example.com')
'https://example.com/'
>>> normalize_url('/test', '/path')
raise Exception
Raises:
* lxml.etree.ParserError
Returns:
* str: normalized URL
"""
if url.startswith('//'):
# add http or https to this kind of url //example.com/
parsed_search_url = urlparse(base_url)
url = '{0}:{1}'.format(parsed_search_url.scheme or 'http', url)
elif url.startswith('/'):
# fix relative url to the search engine
url = urljoin(base_url, url)
# fix relative urls that fall through the crack
if '://' not in url:
url = urljoin(base_url, url)
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parsed_url = urlparse(url)
# add a / at this end of the url if there is no path
if not parsed_url.netloc:
raise Exception('Cannot parse url')
if not parsed_url.path:
url += '/'
return url
def extract_url(xpath_results, base_url):
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"""Extract and normalize URL from lxml Element
Args:
* xpath_results (Union[List[html.HtmlElement], html.HtmlElement]): lxml Element(s)
* base_url (str): Base URL
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Example:
>>> def f(s, search_url):
>>> return searx.utils.extract_url(html.fromstring(s), search_url)
>>> f('<span id="42">https://example.com</span>', 'http://example.com/')
'https://example.com/'
>>> f('https://example.com', 'http://example.com/')
'https://example.com/'
>>> f('//example.com', 'http://example.com/')
'http://example.com/'
>>> f('//example.com', 'https://example.com/')
'https://example.com/'
>>> f('/path?a=1', 'https://example.com')
'https://example.com/path?a=1'
>>> f('', 'https://example.com')
raise lxml.etree.ParserError
>>> searx.utils.extract_url([], 'https://example.com')
raise Exception
Raises:
* Exception
* lxml.etree.ParserError
Returns:
* str: normalized URL
"""
if xpath_results == []:
raise Exception('Empty url resultset')
url = extract_text(xpath_results)
return normalize_url(url, base_url)
def dict_subset(d, properties):
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"""Extract a subset of a dict
Examples:
>>> dict_subset({'A': 'a', 'B': 'b', 'C': 'c'}, ['A', 'C'])
{'A': 'a', 'C': 'c'}
>>> >> dict_subset({'A': 'a', 'B': 'b', 'C': 'c'}, ['A', 'D'])
{'A': 'a'}
"""
result = {}
for k in properties:
if k in d:
result[k] = d[k]
return result
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def list_get(a_list, index, default=None):
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"""Get element in list or default value
Examples:
>>> list_get(['A', 'B', 'C'], 0)
'A'
>>> list_get(['A', 'B', 'C'], 3)
None
>>> list_get(['A', 'B', 'C'], 3, 'default')
'default'
>>> list_get(['A', 'B', 'C'], -1)
'C'
"""
if len(a_list) > index:
return a_list[index]
else:
return default
def get_torrent_size(filesize, filesize_multiplier):
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"""
Args:
* filesize (str): size
* filesize_multiplier (str): TB, GB, .... TiB, GiB...
Returns:
* int: number of bytes
Example:
>>> get_torrent_size('5', 'GB')
5368709120
>>> get_torrent_size('3.14', 'MiB')
3140000
"""
try:
filesize = float(filesize)
if filesize_multiplier == 'TB':
filesize = int(filesize * 1024 * 1024 * 1024 * 1024)
elif filesize_multiplier == 'GB':
filesize = int(filesize * 1024 * 1024 * 1024)
elif filesize_multiplier == 'MB':
filesize = int(filesize * 1024 * 1024)
elif filesize_multiplier == 'KB':
filesize = int(filesize * 1024)
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elif filesize_multiplier == 'TiB':
filesize = int(filesize * 1000 * 1000 * 1000 * 1000)
elif filesize_multiplier == 'GiB':
filesize = int(filesize * 1000 * 1000 * 1000)
elif filesize_multiplier == 'MiB':
filesize = int(filesize * 1000 * 1000)
elif filesize_multiplier == 'KiB':
filesize = int(filesize * 1000)
except:
filesize = None
return filesize
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def convert_str_to_int(number_str):
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"""Convert number_str to int or 0 if number_str is not a number."""
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if number_str.isdigit():
return int(number_str)
else:
return 0
def int_or_zero(num):
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"""Convert num to int or 0. num can be either a str or a list.
If num is a list, the first element is converted to int (or return 0 if the list is empty).
If num is a str, see convert_str_to_int
"""
if isinstance(num, list):
if len(num) < 1:
return 0
num = num[0]
return convert_str_to_int(num)
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def is_valid_lang(lang):
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"""Return language code and name if lang describe a language.
Examples:
>>> is_valid_lang('zz')
False
>>> is_valid_lang('uk')
(True, 'uk', 'ukrainian')
>>> is_valid_lang(b'uk')
(True, 'uk', 'ukrainian')
>>> is_valid_lang('en')
(True, 'en', 'english')
>>> searx.utils.is_valid_lang('Español')
(True, 'es', 'spanish')
>>> searx.utils.is_valid_lang('Spanish')
(True, 'es', 'spanish')
"""
if isinstance(lang, bytes):
lang = lang.decode()
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is_abbr = (len(lang) == 2)
lang = lang.lower()
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if is_abbr:
for l in language_codes:
if l[0][:2] == lang:
return (True, l[0][:2], l[3].lower())
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return False
else:
for l in language_codes:
if l[1].lower() == lang or l[3].lower() == lang:
return (True, l[0][:2], l[3].lower())
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return False
def _get_lang_to_lc_dict(lang_list):
key = str(lang_list)
value = lang_to_lc_cache.get(key, None)
if value is None:
value = dict()
for lc in lang_list:
value.setdefault(lc.split('-')[0], lc)
lang_to_lc_cache[key] = value
return value
def _match_language(lang_code, lang_list=[], custom_aliases={}): # pylint: disable=W0102
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"""auxiliary function to match lang_code in lang_list"""
# replace language code with a custom alias if necessary
if lang_code in custom_aliases:
lang_code = custom_aliases[lang_code]
if lang_code in lang_list:
return lang_code
# try to get the most likely country for this language
subtags = get_global('likely_subtags').get(lang_code)
if subtags:
subtag_parts = subtags.split('_')
new_code = subtag_parts[0] + '-' + subtag_parts[-1]
if new_code in custom_aliases:
new_code = custom_aliases[new_code]
if new_code in lang_list:
return new_code
# try to get the any supported country for this language
return _get_lang_to_lc_dict(lang_list).get(lang_code, None)
def match_language(locale_code, lang_list=[], custom_aliases={}, fallback='en-US'): # pylint: disable=W0102
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"""get the language code from lang_list that best matches locale_code"""
# try to get language from given locale_code
language = _match_language(locale_code, lang_list, custom_aliases)
if language:
return language
locale_parts = locale_code.split('-')
lang_code = locale_parts[0]
# try to get language using an equivalent country code
if len(locale_parts) > 1:
country_alias = get_global('territory_aliases').get(locale_parts[-1])
if country_alias:
language = _match_language(lang_code + '-' + country_alias[0], lang_list, custom_aliases)
if language:
return language
# try to get language using an equivalent language code
alias = get_global('language_aliases').get(lang_code)
if alias:
language = _match_language(alias, lang_list, custom_aliases)
if language:
return language
if lang_code != locale_code:
# try to get language from given language without giving the country
language = _match_language(lang_code, lang_list, custom_aliases)
return language or fallback
def load_module(filename, module_dir):
modname = splitext(filename)[0]
if modname in sys.modules:
del sys.modules[modname]
filepath = join(module_dir, filename)
# and https://docs.python.org/3/library/importlib.html#importing-a-source-file-directly
spec = importlib.util.spec_from_file_location(modname, filepath)
module = importlib.util.module_from_spec(spec)
sys.modules[modname] = module
spec.loader.exec_module(module)
return module
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def to_string(obj):
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"""Convert obj to its string representation."""
if isinstance(obj, str):
return obj
if isinstance(obj, Number):
return str(obj)
if hasattr(obj, '__str__'):
return obj.__str__()
if hasattr(obj, '__repr__'):
return obj.__repr__()
def ecma_unescape(s):
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"""Python implementation of the unescape javascript function
https://www.ecma-international.org/ecma-262/6.0/#sec-unescape-string
https://developer.mozilla.org/fr/docs/Web/JavaScript/Reference/Objets_globaux/unescape
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Examples:
>>> ecma_unescape('%u5409')
''
>>> ecma_unescape('%20')
' '
>>> ecma_unescape('%F3')
'ó'
"""
# "%u5409" becomes "吉"
s = ecma_unescape4_re.sub(lambda e: chr(int(e.group(1), 16)), s)
# "%20" becomes " ", "%F3" becomes "ó"
s = ecma_unescape2_re.sub(lambda e: chr(int(e.group(1), 16)), s)
return s
def get_string_replaces_function(replaces):
rep = {re.escape(k): v for k, v in replaces.items()}
pattern = re.compile("|".join(rep.keys()))
def f(text):
return pattern.sub(lambda m: rep[re.escape(m.group(0))], text)
return f
def get_engine_from_settings(name):
"""Return engine configuration from settings.yml of a given engine name"""
if 'engines' not in settings:
return {}
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for engine in settings['engines']:
if 'name' not in engine:
continue
if name == engine['name']:
return engine
return {}
def get_xpath(xpath_str):
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"""Return cached compiled XPath
There is no thread lock.
Worst case scenario, xpath_str is compiled more than one time.
"""
result = xpath_cache.get(xpath_str, None)
if result is None:
result = XPath(xpath_str)
xpath_cache[xpath_str] = result
return result
def eval_xpath(element, xpath_str):
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"""Equivalent of element.xpath(xpath_str) but compile xpath_str once for all."""
xpath = get_xpath(xpath_str)
return xpath(element)