python练习---登录验证（三次登录）

功能要求：

1、用户登录
2、三次登录失败，如果输入Y/y就再给三次机会，不输入则退出程序
3、支持多用户登录
4、登录成功后退出程序
5、输入用户名或者密码时，随时输入q/Q可以退出程序

a = 0
count = 3
name_list = [
    {'username':'张三','password':'123'},
    {'username':'李四','password':'456'},
    {'username':'王二','password':'789'},

]
while True:
    a += 1
    if a <= 3:
        user_name = input("Please enter your username:").strip()
        if user_name == "q": break
        user_password = input("Please enter your password:").strip()
        if user_password == "q":break
        while True:
            for i in name_list:
                if user_name == i["username"] and user_password == i["password"]:
                    print("login successfully")
                    exit()
            count -= 1
            print(count)
            break
    elif a > 3:
        Y = input("Please enter your y/Y:").strip()
        if Y == "y" or Y == "Y":
            a = 0
        else:
            print("不要脸")
            break