[academicearth] Modernize

youtube_dl/extractor/academicearth.py

@@ -1,4 +1,5 @@
 from __future__ import unicode_literals
+
 import re
 
 from .common import InfoExtractor
@@ -18,15 +19,14 @@ class AcademicEarthCourseIE(InfoExtractor):
     }
 
     def _real_extract(self, url):
-        m = re.match(self._VALID_URL, url)
-        playlist_id = m.group('id')
+        playlist_id = self._match_id(url)
 
         webpage = self._download_webpage(url, playlist_id)
         title = self._html_search_regex(
-            r'<h1 class="playlist-name"[^>]*?>(.*?)</h1>', webpage, u'title')
+            r'<h1 class="playlist-name"[^>]*?>(.*?)</h1>', webpage, 'title')
         description = self._html_search_regex(
             r'<p class="excerpt"[^>]*?>(.*?)</p>',
-            webpage, u'description', fatal=False)
+            webpage, 'description', fatal=False)
         urls = re.findall(
             r'<li class="lecture-preview">\s*?<a target="_blank" href="([^"]+)">',
             webpage)