python批量修改文件名

import sys, string, os, shutil

def RenameFiles(srcdir, prefix):
    srcfiles = os.listdir(srcdir)
    index = 1
    for srcfile in srcfiles:
        srcfilename = os.path.splitext(srcfile)[0][1:]
        sufix = os.path.splitext(srcfile)[1]

        destfile = srcdir + "//" + prefix + "_%04d"%(index) + sufix
        srcfile = os.path.join(srcdir, srcfile)
        os.rename(srcfile, destfile)
        index += 1
        print destfile
srcdir = "E://test"
prefix = "chin"
RenameFiles(srcdir, prefix)