[enh] add re-usable func to filter text

searx/engines/brave.py

@@ -132,6 +132,7 @@ from lxml import html
 from searx import locales
 from searx.utils import (
     extract_text,
+    extr,
     eval_xpath,
     eval_xpath_list,
     eval_xpath_getindex,
@@ -252,11 +253,7 @@ def response(resp):
     if brave_category in ('search', 'goggles'):
         return _parse_search(resp)
 
-    datastr = ""
-    for line in resp.text.split("\n"):
-        if "const data = " in line:
-            datastr = line.replace("const data = ", "").strip()[:-1]
-            break
+    datastr = extr(resp.text, "const data = ", ";\n").strip()
 
     json_data = js_variable_to_python(datastr)
     json_resp = json_data[1]['data']['body']['response']

searx/engines/duckduckgo.py

@@ -392,7 +392,9 @@ def fetch_traits(engine_traits: EngineTraits):
     SearXNG's locale.
 
     """
-    # pylint: disable=too-many-branches, too-many-statements
+    # pylint: disable=too-many-branches, too-many-statements, disable=import-outside-toplevel
+    from searx.utils import extr, js_variable_to_python
+
     # fetch regions
 
     engine_traits.all_locale = 'wt-wt'
@@ -403,11 +405,9 @@ def fetch_traits(engine_traits: EngineTraits):
     if not resp.ok:  # type: ignore
         print("ERROR: response from DuckDuckGo is not OK.")
 
-    pos = resp.text.find('regions:{') + 8  # type: ignore
-    js_code = resp.text[pos:]  # type: ignore
-    pos = js_code.find('}') + 1
-    regions = json.loads(js_code[:pos])
+    js_code = extr(resp.text, 'regions:', ',snippetLengths')
 
+    regions = json.loads(js_code)
     for eng_tag, name in regions.items():
 
         if eng_tag == 'wt-wt':
@@ -439,12 +439,9 @@ def fetch_traits(engine_traits: EngineTraits):
 
     engine_traits.custom['lang_region'] = {}
 
-    pos = resp.text.find('languages:{') + 10  # type: ignore
-    js_code = resp.text[pos:]  # type: ignore
-    pos = js_code.find('}') + 1
-    js_code = '{"' + js_code[1:pos].replace(':', '":').replace(',', ',"')
-    languages = json.loads(js_code)
+    js_code = extr(resp.text, 'languages:', ',regions')
 
+    languages = js_variable_to_python(js_code)
     for eng_lang, name in languages.items():
 
         if eng_lang == 'wt_WT':

searx/engines/qwant.py

@@ -312,13 +312,12 @@ def fetch_traits(engine_traits: EngineTraits):
     # pylint: disable=import-outside-toplevel
     from searx import network
     from searx.locales import region_tag
+    from searx.utils import extr
 
     resp = network.get(about['website'])
-    text = resp.text
-    text = text[text.find('INITIAL_PROPS') :]
-    text = text[text.find('{') : text.find('</script>')]
+    json_string = extr(resp.text, 'INITIAL_PROPS = ', '</script>')
 
-    q_initial_props = loads(text)
+    q_initial_props = loads(json_string)
     q_locales = q_initial_props.get('locales')
     eng_tag_list = set()
 

searx/engines/vimeo.py

@@ -7,6 +7,8 @@ from urllib.parse import urlencode
 from json import loads
 from dateutil import parser
 
+from searx.utils import extr
+
 # about
 about = {
     "website": 'https://vimeo.com/',
@@ -23,7 +25,7 @@ paging = True
 
 # search-url
 base_url = 'https://vimeo.com/'
-search_url = base_url + '/search/page:{pageno}?{query}'
+search_url = base_url + 'search/page:{pageno}?{query}'
 
 
 # do search-request
@@ -36,9 +38,8 @@ def request(query, params):
 # get response from search-request
 def response(resp):
     results = []
-    data_start_pos = resp.text.find('{"filtered"')
-    data_end_pos = resp.text.find(';\n', data_start_pos + 1)
-    data = loads(resp.text[data_start_pos:data_end_pos])
+
+    data = loads(extr(resp.text, 'var data = ', ';\n'))
 
     # parse results
     for result in data['filtered']['data']:

searx/engines/youtube_noapi.py

@@ -7,6 +7,8 @@ from functools import reduce
 from json import loads, dumps
 from urllib.parse import quote_plus
 
+from searx.utils import extr
+
 # about
 about = {
     "website": 'https://www.youtube.com/',
@@ -109,8 +111,8 @@ def parse_next_page_response(response_text):
 
 def parse_first_page_response(response_text):
     results = []
-    results_data = response_text[response_text.find('ytInitialData') :]
-    results_data = results_data[results_data.find('{') : results_data.find(';</script>')]
+    results_data = extr(response_text, 'ytInitialData = ', ';</script>')
+
     results_json = loads(results_data) if results_data else {}
     sections = (
         results_json.get('contents', {})

searx/utils.py

@@ -2,6 +2,9 @@
 """Utility functions for the engines
 
 """
+
+from __future__ import annotations
+
 import re
 import importlib
 import importlib.util
@@ -371,6 +374,35 @@ def convert_str_to_int(number_str: str) -> int:
     return 0
 
 
+def extr(txt: str, begin: str, end: str, default: str = ""):
+    """Extract the string between ``begin`` and ``end`` from ``txt``
+
+    :param txt:     String to search in
+    :param begin:   First string to be searched for
+    :param end:     Second string to be searched for after ``begin``
+    :param default: Default value if one of ``begin`` or ``end`` is not
+                    found.  Defaults to an empty string.
+    :return: The string between the two search-strings ``begin`` and ``end``.
+             If at least one of ``begin`` or ``end`` is not found, the value of
+             ``default`` is returned.
+
+    Examples:
+      >>> extr("abcde", "a", "e")
+      "bcd"
+      >>> extr("abcde", "a", "z", deafult="nothing")
+      "nothing"
+
+    """
+
+    # From https://github.com/mikf/gallery-dl/blob/master/gallery_dl/text.py#L129
+
+    try:
+        first = txt.index(begin) + len(begin)
+        return txt[first : txt.index(end, first)]
+    except ValueError:
+        return default
+
+
 def int_or_zero(num: Union[List[str], str]) -> int:
     """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).