[generic] Refactor `_extract_rss`

Closes #3738

yt_dlp/extractor/generic.py

@@ -129,6 +129,7 @@ from ..utils import (
     sanitized_Request,
     smuggle_url,
     str_or_none,
+    try_call,
     unescapeHTML,
     unified_timestamp,
     unsmuggle_url,
@@ -2536,66 +2537,44 @@ class GenericIE(InfoExtractor):
         self._downloader.write_debug(f'Identified a {name}')
 
     def _extract_rss(self, url, video_id, doc):
-        playlist_title = doc.find('./channel/title').text
-        playlist_desc_el = doc.find('./channel/description')
-        playlist_desc = None if playlist_desc_el is None else playlist_desc_el.text
-
         NS_MAP = {
             'itunes': 'http://www.itunes.com/dtds/podcast-1.0.dtd',
         }
 
         entries = []
         for it in doc.findall('./channel/item'):
-            next_url = None
-            enclosure_nodes = it.findall('./enclosure')
-            for e in enclosure_nodes:
-                next_url = e.attrib.get('url')
-                if next_url:
-                    break
-
-            if not next_url:
-                next_url = xpath_text(it, 'link', fatal=False)
-
+            next_url = next(
+                (e.attrib.get('url') for e in it.findall('./enclosure')),
+                xpath_text(it, 'link', fatal=False))
             if not next_url:
                 continue
 
-            if it.find('guid').text is not None:
-                next_url = smuggle_url(next_url, {'force_videoid': it.find('guid').text})
+            guid = try_call(lambda: it.find('guid').text)
+            if guid:
+                next_url = smuggle_url(next_url, {'force_videoid': guid})
 
             def itunes(key):
-                return xpath_text(
-                    it, xpath_with_ns('./itunes:%s' % key, NS_MAP),
-                    default=None)
-
-            duration = itunes('duration')
-            explicit = (itunes('explicit') or '').lower()
-            if explicit in ('true', 'yes'):
-                age_limit = 18
-            elif explicit in ('false', 'no'):
-                age_limit = 0
-            else:
-                age_limit = None
+                return xpath_text(it, xpath_with_ns(f'./itunes:{key}', NS_MAP), default=None)
 
             entries.append({
                 '_type': 'url_transparent',
                 'url': next_url,
-                'title': it.find('title').text,
+                'title': try_call(lambda: it.find('title').text),
                 'description': xpath_text(it, 'description', default=None),
-                'timestamp': unified_timestamp(
-                    xpath_text(it, 'pubDate', default=None)),
-                'duration': int_or_none(duration) or parse_duration(duration),
+                'timestamp': unified_timestamp(xpath_text(it, 'pubDate', default=None)),
+                'duration': parse_duration(itunes('duration')),
                 'thumbnail': url_or_none(xpath_attr(it, xpath_with_ns('./itunes:image', NS_MAP), 'href')),
                 'episode': itunes('title'),
                 'episode_number': int_or_none(itunes('episode')),
                 'season_number': int_or_none(itunes('season')),
-                'age_limit': age_limit,
+                'age_limit': {'true': 18, 'yes': 18, 'false': 0, 'no': 0}.get((itunes('explicit') or '').lower()),
             })
 
         return {
             '_type': 'playlist',
             'id': url,
-            'title': playlist_title,
-            'description': playlist_desc,
+            'title': try_call(lambda: doc.find('./channel/title').text),
+            'description': try_call(lambda: doc.find('./channel/description').text),
             'entries': entries,
         }