day02代码

1.while.....else.....语句，break，continue，if，while，用户交互，输出，运算符

# 用户有三次登录机会
_username = 'tom'
_password = 'abc123'
count = 1
while count <= 3:
    name = input("请输入用户名：")
    password = input("请输入密码：")
    if name == _username and password == _password:
        print("登录成功")
        break
    else:
        print("请再试一次，还剩%s机会!" % (3-count))  # 提示用户还剩几次机会
        if count == 3:
            choice = input("如果想再次尝试，需要输入?Yes")
            if choice == 'Yes' or choice == 'yes':  # 如果choice值为True或False,count值为1
                count = 1
                continue
        else:
            pass
    count += 1
else:
    print("不要脸")