chang_Ext.py

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

import os,sys,optparse

def main():
  parser=optparse.OptionParser('usage chageExt.py -s <source ext> -d <dest ext>')
  parser.add_option('-s', dest='srcext', type='string', help='source ext')
  parser.add_option('-d', dest='destext', type='string', help='dest ext')

  (options, args)=parser.parse_args()

  srcext =options.srcext
  destext=options.destext

  if (srcext== None) | (destext==None):
    print parser.usage
    exit(0)

  for base, dirs, names in os.walk("./"):
    for name in names:
      if os.path.splitext(name)[1].lower()=="."+srcext :
        src=os.path.join(base, name)
        dest=os.path.splitext(src)[0]+"."+destext
        #print src
        #print dest
        os.rename(src, dest)

if __name__== '__main__':
  main()