第一天 简单的python认证登陆代码

#!/usr/bin/env python3
# -*- coding:utf-8 -*-
# name:zzyu

welcome = '''
-----------welcome to home------------
请选择是否为新用户，请在下面提示中输入<y or n>'''
print (welcome)
new_user = str(input("请输入<y or n>:"))
if new_user == "y":
    print ("欢迎注册")
    username = str(input("请输入用户名："))
    userpass = str(input("请设置密码："))
    with open('user_pass.txt','a') as file:
        file.write("{_username} {_userpass} \n".format(_username=username,_userpass=userpass))
        print("欢迎您：{_user_name}".format(_user_name=username))
elif new_user == "n":
    dl = str(input("您是否选择登陆，请输入<y or n>:"))
    if dl == "y":
        username = str(input("请输入用户名："))
        userpass = str(input("请设置密码："))
        with open('user_pass.txt','r') as file1:
#            for check in file1.readlines():
            check = file1.read()
            if username in check and userpass in check:
                print ("您好，欢迎回家！！！")
            else:
                count = 0
                while count < 2:
                    print ("您输入的用户名或密码有误，请重新输入....")
                    username = str(input("请输入用户名："))
                    userpass = str(input("请设置密码："))
                    count += 1
                    if count == 2:
                        print("您的账号已被锁定......")
else:
    print ("BYE BYE")