python 批量修改文件名

import os

path=input("请输入图片目录的路径:")
if path[-1]!='/':
    path+='/'
f=os.listdir(path)

print("pictures count:", len(f))
for i in range(0, len(f)):
    oldname=path+f[i]
    newname=path+'liudehua_'+str(i).rjust(4,'0')+oldname[oldname.rfind("."):]

    os.rename(oldname,newname)