+ def _extract_playlist(self, playlist_id):
+ url = self._TEMPLATE_URL % playlist_id
+ page = self._download_webpage(url, playlist_id)
+
+ for match in re.findall(r'<div class="yt-alert-message">([^<]+)</div>', page):
+ match = match.strip()
+ # Check if the playlist exists or is private
+ if re.match(r'[^<]*(The|This) playlist (does not exist|is private)[^<]*', match):
+ raise ExtractorError(
+ 'The playlist doesn\'t exist or is private, use --username or '
+ '--netrc to access it.',
+ expected=True)
+ elif re.match(r'[^<]*Invalid parameters[^<]*', match):
+ raise ExtractorError(
+ 'Invalid parameters. Maybe URL is incorrect.',
+ expected=True)
+ elif re.match(r'[^<]*Choose your language[^<]*', match):
+ continue
+ else:
+ self.report_warning('Youtube gives an alert message: ' + match)
+
+ # Extract the video ids from the playlist pages
+ def _entries():
+ more_widget_html = content_html = page
+ for page_num in itertools.count(1):
+ matches = re.finditer(self._VIDEO_RE, content_html)
+ # We remove the duplicates and the link with index 0
+ # (it's not the first video of the playlist)
+ new_ids = orderedSet(m.group('id') for m in matches if m.group('index') != '0')
+ for vid_id in new_ids:
+ yield self.url_result(vid_id, 'Youtube', video_id=vid_id)
+
+ mobj = re.search(r'data-uix-load-more-href="/?(?P<more>[^"]+)"', more_widget_html)
+ if not mobj:
+ break
+
+ more = self._download_json(
+ 'https://youtube.com/%s' % mobj.group('more'), playlist_id,
+ 'Downloading page #%s' % page_num,
+ transform_source=uppercase_escape)
+ content_html = more['content_html']
+ if not content_html.strip():
+ # Some webpages show a "Load more" button but they don't
+ # have more videos
+ break
+ more_widget_html = more['load_more_widget_html']
+
+ playlist_title = self._html_search_regex(
+ r'(?s)<h1 class="pl-header-title[^"]*">\s*(.*?)\s*</h1>',
+ page, 'title')
+
+ return self.playlist_result(_entries(), playlist_id, playlist_title)
+