需求：在一个数据文件中，让用户输入信息 with open(r'bd.py',mode='rt',encoding='utf-8') as f:     count=0     while count<=3:         name=input("please input account: ")         password=input("please input password: ")         for msg in f:             if name == msg.strip('\n').split(':')[0] and password == msg.strip('\n').split(':')[1]:                 print("login successful")                 break         else:             print("sb")             count+=1