title: Is there a way to get YT url or video ID from playlist with pafy?
body: <p>I am trying to make a program that takes YT playlist and play all it's content.</p>
  
  <p>I've installed all components needed for pafy to run with python3. Everything I've tried works as it's expected, except the bellow part of the code.</p>
  
  <pre><code>plurl = "https://www.youtube.com/playlist?list=PL634F2B56B8C346A2"
  playlist = pafy.get_playlist(plurl)
  url = playlist['items'][21]['pafy'].getbest().url
  video = pafy.new(url)
  </code></pre>
  
  <p>When <code>pafy.new()</code> is called, gives an error because of too long url:</p>
  
  <pre><code>Need 11 character video id or the URL of the video. Got https://r2---sn-bavc5aoxu-nv4l.googlevideo.com/videoplayback?ms=au%2Crdu&amp;sparams=clen%2Cdur%2Cei%2Cgir%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Cratebypass%2Crequiressl%2Csource%2Cexpire&amp;mv=m&amp;mt=1554899146&amp;requiressl=yes&amp;ip=37.157.173.53&amp;pl=19&amp;id=o-AGQZkyoEvykUGae7O4v_Ycmuj4jJBYdgafcfLBQ5S4Dd&amp;mn=sn-bavc5aoxu-nv4l%2Csn-nv47lnsr&amp;mm=31%2C29&amp;source=youtube&amp;lmt=1387649403290510&amp;ei=POGtXJzdIo_ugAeEiL_wAQ&amp;c=WEB&amp;key=yt6&amp;mime=video%2Fmp4&amp;gir=yes&amp;itag=18&amp;clen=5461830&amp;fvip=2&amp;expire=1554920860&amp;ratebypass=yes&amp;dur=206.100&amp;initcwndbps=1573750&amp;ipbits=0&amp;signature=AAA8B36CD3B402F587F874956595ACB928806C4F.D36C0A79E7F1727DB872425E696DBFC550AA7DF6 
  </code></pre>
  
  <p>Is there a way I can get normal url or video ID ?</p>