批量改后缀

import os

# 列出当前目录下所有的文件
os.chdir(r"\\Win-l4hi2f9h2r4\店铺数据\2016\花吉\10\media")
files =os.listdir (r"\\Win-l4hi2f9h2r4\店铺数据\2016\花吉\10\media")

for filename in files:
    portion = list(os.path.splitext(filename))
    newname = portion[0] + ".jpg"
    os.rename(filename,newname)