Pythonファイル名の一括変更(ファイル名の文字列を削除または置換)

import re
import os


path = "E:\B" #           



originalname = '123' #123          123   
replacename = '321' #321         ，      originalname，  replacename = ''   
def main1(path1):
    files = os.listdir(path1)  #              
    for file in files: #     
        if os.path.isdir(path1 + '\\' + file):
            main1(path1 + '\\' + file)
        else:
            files2 = os.listdir(path1 + '\\')
            for file1 in files2:
                if originalname in file1:
                    # ‘’    X  
                    n = str(path1 + '\\' + file1.replace(originalname,replacename))
                    n1 = str(path1 + '\\' + str(file1))
                    try:
                        os.rename(n1, n)
                    except IOError:
                        continue
main1(path)