python实现批量改文件名称的方法

#-*- coding: UTF-8 -*-
import os
filenames = os.listdir(os.getcwd())
for name in filenames:
  print(name)
for num in range(0,len(filenames)):
  if(num<10):
    print()
    print(filenames[num])
    os.rename(filenames[num],'0'+str(num)+'.png')
  else:
    os.rename(filenames[num],str(num)+'.png')