http://ansuz.sooke.bc.ca/entry/23

  #!python3
  """Open url in VLC — Pythonista for iOS app extension.
  
  1. take media url from appex(share)/clipboard/command-line
  2. open it in VLC iphone app
  
  e.g., to listen to Youtube video in the background.
  
  It accepts a media url from any site supported by youtube_dl 
  https://rg3.github.io/youtube-dl/supportedsites.html
  """
  import sys
  from urllib.parse import quote
  
  import youtube_dl
  
  import appex
  import clipboard
  import console
  
  import appex_webbrowser as webbrowser
  
  def open(webpage_url):
      """Play media on *webpage_url* in VLC"""
      with youtube_dl.YoutubeDL(dict(forceurl=True)) as ydl:
          r = ydl.extract_info(webpage_url, download=False)
          media_url = r['formats'][-1]['url']
      # play the url in VLC
      # vlc:// + url leads to a popup
      # https://wiki.videolan.org/Documentation:IOS/#x-callback-url
      webbrowser.open('vlc-x-callback://x-callback-url/stream?url=' + quote(media_url) )
      
  
  def main():
      if not appex.is_running_extension():
          if len(sys.argv) == 2:
              url = sys.argv[1]
          else:
              url = clipboard.get()
      else:
          url = appex.get_url() or appex.get_text()
      if url:
          open(url)
          console.hud_alert('Done.')
      else:
          console.hud_alert('No input URL found.')
  
  if __name__ == '__main__':
      console.show_activity()
      try:
          main()
      finally:
          console.hide_activity()

  """webbrowser.open() replacement for app extensions in Pythonista for iOS.
  """
  from objc_util import nsurl,UIApplication
  
  
  def open(url):
      app = UIApplication.sharedApplication()
      app.openURL_(nsurl(url))