To regroup x avis files which have been splitted

gistfile1.txt

import re
from subprocess import call
import sys

import os

rootdir = '.'

dictOfFilms = {}

for subdir, dirs, files in os.walk(rootdir):
    for file in files:
        if file.endswith(".avi") and re.search("_[0-9].avi", file) is None:
            prefix = file.replace('.avi', '')
            regex = re.compile(prefix + "_[0-9].avi")
            for subfile in files:
                if regex.match(subfile):
                    if prefix not in dictOfFilms:
                        dictOfFilms[prefix] = [file]
                    dictOfFilms[prefix].append(subfile)
for key, value in dictOfFilms.iteritems():
    toGroupProperly = ["'" + a + "'" for a in value]
    command = "cat " + " ".join(
        toGroupProperly) + " > tmp.avi && mencoder -forceidx -oac copy -ovc copy tmp.avi -o 'Converted/" + key + ".avi' && rm -f tmp.avi"
    if 'go' in sys.argv:
        call(command, shell=True)
    print command