title: Why does YoutubeDL extract only the first index of a playlist?
body: <p>I'm doing a project that's related to playlists and I made a class which inherits from YoutubeDL.</p>
  
  <pre><code>class Playlist(youtube_dl.YoutubeDL):
      info = {}
  
      """
      Base class for any playlist. Inherits from youtube_dl.YoutubeDL and overrides some methods to make sure that the
      link is an actual playlist and implements some cool stuff to make playlist loading easier.
      :var info: the stored information from the extract_info() method
      :type info: dict
      """
  
      def extract_info(self, url, download=False, ie_key=None, extra_info=None, process=True, force_generic_extractor=False):
          """
          Loads the playlist info and make sures the link is a playlist
  
          :param url: the link with the info to be loaded
          :param download: will it download?
          :param ie_key: see youtube_dl's doc
          :param extra_info: see youtube_dl's doc
          :param process: see youtube_dl's doc
          :param force_generic_extractor: see youtube_dl's doc
          :return: extract_info(...)["entries"] = self.info
          :rtype: list
          """
          info = super(Playlist, self).extract_info(url, download, ie_key, extra_info, process, force_generic_extractor)
  
  
          if "_type" not in info:
              raise BaseException("\"_type\" not in \"info\"!\n" + info.__str__())
          if info["_type"] != "playlist":
              raise NotPlaylistError("The url %s does not appear to be a playlist" % url)
  
          self.info = info["entries"]
  
          return self.info
  
      def download(self, url_list=list()):
          """
          The inherited download method - now can be used without parameters. If no url_list specified, uses self.info
          :param url_list: the url list to be downloaded
          :return: nothing
          :rtype: None
          """
  
          super(Playlist, self).download(url_list if url_list else self.info)
  </code></pre>
  
  <p>So I've simply added a playlist with <code>Playlist().extract_info(my_url)</code>. But it raised a <code>KeyError</code> which was caused by a <code>"_type"</code> key. Thus I played with the code a bit and I found out the code was downloading only the first index of the entire playlist (the actual code posted here is already handling that by raising a <code>BaseError</code>). Why is this happening?</p>