用户登陆（三次机会）


count = 0
while count < 3:
    user = input('请输入账号：')
    pwd = input('请输入密码：')
    if user == 'admin' and pwd == '123456':
        print("登陆成功")
        break
    else:
        print("账号或密码错误，请重新输入")
    count = count + 1