define a walk() function

#!/usr/bin/env python
#-*- coding:utf-8 -*-

import os
impost sys

def walk(path):
    isdir, isfile, join = os.paht.isdir, os.path.isfile, os.path.join
    lsdir = os.listdir(path)
    dirs = [i for i in lsdir if isdir(join(path, i))]
    files = [i for i in lsdir if isfile(join(path, i))]
    if dirs:
        for d in dirs:
            for x in walk(join(path, d)):
                yield(x)
    yield(path, dirs, files)

if __name__ == "__main__":
    for path, dirs, files in walk(sys.argv[1]):
        for f in files:
            print os.path.join(path, f)