Change improve usage of the optional regex library.

Limit possible regex errors to 20% of extra_info up to max 3 errors.

CHANGES.md

@@ -1,6 +1,7 @@
 ### 0.13.6 (2017-12-13 01:50:00 UTC)
 
 * Change improve multi episode release search
+* Change improve usage of the optional regex library
 
 
 ### 0.13.5 (2017-12-11 21:45:00 UTC)

gui/slick/interfaces/default/config_search.tmpl

@@ -58,8 +58,12 @@
 						</div>
 						<div id="content_download_propers">
 							<span class="component-desc">
+#if $getVar('using_regex', False)
+                                <p>Optional <a href="https://pypi.python.org/pypi/regex" target="_blank">regex python library</a> is being used</p>
+#else
                                 <p>Optional: to improve matching, install the OS dependent <a href="https://pypi.python.org/pypi/regex" target="_blank">regex python library</a></p>
                                 <p>at a command line, simply enter ... <code>python -m pip install regex</code></p>
+#end if
                             </span>
 							<div class="field-pair">
 								<label>

sickbeard/name_parser/parser.py

@@ -656,8 +656,13 @@ class ParseResult(object):
         if None is regex:
             return re.sub(ep_regex, '', e_i_n_n, flags=re.I)
 
-        return regex.sub(r'(%s){e<=%d}' % (
-            ep_regex, trunc(len(re.findall(r'\w', ep_regex)) / 5)), '', e_i_n_n, flags=regex.I | regex.B)
+        er = trunc(len(re.findall(r'\w', ep_regex)) / 5)
+        try:
+            me = trunc(len(e_i_n_n) / 5)
+            me = min(3, me)
+        except (StandardError, Exception):
+            me = 3
+        return regex.sub(r'(%s){e<=%d}' % (ep_regex, (er, me)[er > me]), '', e_i_n_n, flags=regex.I | regex.B)
 
     def get_extra_info_no_name(self):
         extra_info_no_name = self.extra_info

sickbeard/webserve.py

@@ -4976,6 +4976,12 @@ class ConfigSearch(Config):
                                      show.rls_require_words.strip()]
         t.using_rls_require_words.sort(lambda x, y: cmp(x[1], y[1]), reverse=False)
         t.propers_intervals = search_propers.ProperSearcher().search_intervals
+        t.using_regex = False
+        try:
+            from sickbeard.name_parser.parser import regex
+            t.using_regex = None is not regex
+        except (StandardError, Exception):
+            pass
         return t.respond()
 
     def saveSearch(self, use_nzbs=None, use_torrents=None, nzb_dir=None, sab_username=None, sab_password=None,