[enh][fix] support base_urls without language code ++ extra whitespaces removed

searx/engines/mediawiki.py

@@ -11,6 +11,7 @@
 # @todo        content
 
 from json import loads
+from string import Formatter
 from urllib import urlencode, quote
 
 # engine dependent config
@@ -21,25 +22,35 @@ number_of_results = 1
 
 # search-url
 base_url = 'https://{language}.wikipedia.org/'
-search_url = base_url + 'w/api.php?action=query&list=search&{query}&srprop=timestamp&format=json&sroffset={offset}&srlimit={limit}'  # noqa
+search_url = base_url + 'w/api.php?action=query\
+                                  &list=search\
+                                  &{query}\
+                                  &srprop=timestamp\
+                                  &format=json\
+                                  &sroffset={offset}\
+                                  &srlimit={limit}'
 
 
 # do search-request
 def request(query, params):
     offset = (params['pageno'] - 1) * number_of_results
+    string_args = dict(query=urlencode({'srsearch': query}),
+                        offset=offset,
+                        limit=number_of_results)
+    format_strings = Formatter().parse(base_url)
 
     if params['language'] == 'all':
         language = 'en'
     else:
         language = params['language'].split('_')[0]
 
+    if len(format_strings) > 1:
+        string_args['language'] = language
+
     # write search-language back to params, required in response
     params['language'] = language
 
-    params['url'] = search_url.format(query=urlencode({'srsearch': query}),
-                                      offset=offset,
-                                      limit=number_of_results,
-                                      language=language)
+    params['url'] = search_url.format(**string_args)
 
     return params