利用Python将文件名字改为小写

import os
path="D:/数据/测试数据"
def rename (path):
  filenames = os.listdir(path)
  for filename in filenames:
    lowerfilename = filename.lower()
    file = os.path.join(path,filename)
    new_file = os.path.join(path,lowerfilename)
    if os.path.isdir(file):
      rename(file)
    else:
      os.rename(file,new_file)
rename(path)