#!/usr/bin/env python
#
# Author: Martin Matusiak <numerodix@gmail.com>
# Licensed under the GNU Public License, version 3.
#
# revision 1 - support multiple digit runs in filenames

import os, string, glob, re, sys

def renseq():
    if (len(sys.argv) != 2):
        print "Usage:\t" + sys.argv[0] + " <num_digits>"
    else:
        ren_seq_files(sys.argv[1])


def ren_seq_files(num_digits):
    files = glob.glob("*")
    for filename in files:
        m = re.search("(.*)(\..*)", filename)
        ext = ""
        if m: (filename, ext) = m.groups()

        digit_runs = re.finditer("([0-9]+)", filename)
        spans = [m.span() for m in digit_runs if digit_runs]
        if spans:
            spans.reverse()
            arr = list(filename)
            for (s, e) in spans:
                arr[s:e] = string.zfill(str( int(filename[s:e]) ), int(num_digits))
            os.rename(filename+ext, "".join(arr)+ext)
    


if __name__ == "__main__":
    renseq()