批量修改当前文件夹中txt中的内容

import re

import os

files = os.listdir('./')

def replaceStr(file):

    with open(file, 'r', encoding='utf-8') as f:

        str = f.read()

        print(str)

        str1 = re.sub('abd', 'cba', str)

        with open(file,'w', encoding='utf-8') as f:

            f.write(str1)

print(files)

for f in files:

    if f.find('.txt') > -1 :

        replaceStr(f)