PYTHON登录认证

user_list=[['user1','123',0],['user2','qwe',0]]
while True:
    username=input("please input username:")
    if username not in [user[0] for user in user_list]:
        print("用户名不存在，请重新输入")
    else:
        for user in user_list:
            if username==user[0]:
                times=user[2]
                if times==3:
                    print("用户已被锁定，请使用其他帐号登陆")
                else:
                    pwd=input("please input password:")
                    if pwd==user[1]:
                        print("welcome")
                        exit()
                    else:
                        print("the password is error")
                        user[2]+=1