python批量修改图片格式

import os
from PIL import Image

def png_to_jpg(filepath):
for root, _, files in os.walk(filepath):
for file in files:
if file.endswith('png'):
name,g = file.split('.')
new = name + ".jpg"
oldpath = os.path.join(root,file)
newpath = os.path.join(root,new)
img = Image.open(oldpath)
img.save(newpath)
else:
pass

def rm_png(filepath):
for root, _, files in os.walk(filepath):
for file in files:
if file.endswith('png'):
dir = os.path.join(root,file)
os.remove(dir)

else:
pass

if __name__ == '__main__':
filepath = 'C:/Users/mailb/Desktop/muchang/11'
png_to_jpg(filepath)
rm_png(filepath)