Consider the following URLs
http://m3u.com/tunein.m3u http://asxsomeurl.com/listen.asx:8024 http://www.plssomeotherurl.com/station.pls?id=111 http://22.198.133.16:802
Use urlparse, that'll get most of the above sorted:
http://docs.python.org/library/urlparse.html
then split the "path" up. You might be able to split the path up using os.path.split, but your example 2 with the :8024 on the end needs manual handling. Are your file extensions always three letters? Or always letters and numbers? Use a regular expression.