rename subtitle files to match video files in same folder

namesub.py

'''
Rename subtitle files in same folder to match the movie file
(for xbmc-share folder)

Jarkko Saltiola 2013
'''
import os
import re

video_types = ["mkv","avi"]
subtitle_types = ["sub", "srt"]

all_files = os.listdir('.')  # List current directory items

episodes = [f for f in all_files if f[-3:] in video_types]
subtitles = [f for f in all_files if f[-3:] in subtitle_types]

unmatched_subtitles = [f for f in subtitles if f[:-4] not in episodes]

# Search matching videos for unmatched subtitles, rename subtitles
for subtitle in unmatched_subtitles:
    print 'Finding matches for: "%s"' % subtitle

    # Find out subtitle's episode-number
    # RE-match 1-2 digits without preceding "Part "
    episode_number = re.findall(r"(?<!Part )\d{1,2}", subtitle)[0]
    print '  Episode number is: "%s"' % episode_number
    for episode in episodes:
        match = re.search("(?<!Part )%s" % episode_number, episode)
        if match:
            new_filename = episode[:-3] + subtitle[-3:]
            print '    !found match: "%s", new filename: "%s"' % (episode,new_filename)
            if new_filename not in subtitles:
                print '    !Renaming:    "%s" -> "%s"' % (subtitle,new_filename)
                os.rename(subtitle,new_filename)