[radiobremen] Make code more readable and more resilient to failures

youtube_dl/extractor/radiobremen.py

@@ -29,15 +29,21 @@ class RadioBremenIE(InfoExtractor):
         video_id = self._match_id(url)
 
         meta_url = "http://www.radiobremen.de/apps/php/mediathek/metadaten.php?id=%s" % video_id
-        meta_doc = self._download_webpage(meta_url, video_id, 'Downloading metadata')
-        title = self._html_search_regex("<h1.*>(?P<title>.+)</h1>", meta_doc, "title")
-        description = self._html_search_regex("<p>(?P<description>.*)</p>", meta_doc, "description")
-        duration = parse_duration(
-            self._html_search_regex("L&auml;nge:</td>\s+<td>(?P<duration>[0-9]+:[0-9]+)</td>", meta_doc, "duration"))
-
-        page_doc = self._download_webpage(url, video_id, 'Downloading video information')
-        pattern = "ardformatplayerclassic\(\'playerbereich\',\'(?P<width>[0-9]+)\',\'.*\',\'(?P<video_id>[0-9]+)\',\'(?P<secret>[0-9]+)\',\'(?P<thumbnail>.+)\',\'\'\)"
-        mobj = re.search(pattern, page_doc)
+        meta_doc = self._download_webpage(
+            meta_url, video_id, 'Downloading metadata')
+        title = self._html_search_regex(
+            r"<h1.*>(?P<title>.+)</h1>", meta_doc, "title")
+        description = self._html_search_regex(
+            r"<p>(?P<description>.*)</p>", meta_doc, "description", fatal=False)
+        duration = parse_duration(self._html_search_regex(
+            r"L&auml;nge:</td>\s+<td>(?P<duration>[0-9]+:[0-9]+)</td>",
+            meta_doc, "duration", fatal=False))
+
+        page_doc = self._download_webpage(
+            url, video_id, 'Downloading video information')
+        mobj = re.search(
+            r"ardformatplayerclassic\(\'playerbereich\',\'(?P<width>[0-9]+)\',\'.*\',\'(?P<video_id>[0-9]+)\',\'(?P<secret>[0-9]+)\',\'(?P<thumbnail>.+)\',\'\'\)",
+            page_doc)
         video_url = (
             "http://dl-ondemand.radiobremen.de/mediabase/%s/%s_%s_%s.mp4" %
             (video_id, video_id, mobj.group("secret"), mobj.group('width')))