Question

我正在编写一个程序，要求用户输入密码。如果密码与我设置的常量匹配，则会打印出＆＃34;成功登录的消息＆＃34;。但是，如果密码不正确，则会提供剩余的猜测次数，并要求用户重试。该程序应在3次错误猜测后结束，但即使在使用3次尝试后仍继续询问。我认为问题出在我的while循环中，但我不确定。

代码：

def main():
    PASSWORD = "apple"
    ALLOWED = 3

    password = input("Enter the password: ")
    while password != PASSWORD :
        ALLOWED = ALLOWED - 1
        print("Wrong. You have", ALLOWED, "guesses left")

        if ALLOWED == 0:
                    print("You have been locked out")
        password = input("Enter again ")            


    print("You have successfully logged into the system")



main()

Answer 1

现在你永远不会退出你的while循环。要突破它，请使用break关键字。要完全退出程序，您需要import sys和sys.exit() 我建议将这些添加到您的if ALLOWED == 0声明中。

Answer 2

您需要使用break退出循环，或添加辅助条件，否则无论如何都会继续进行，直到密码正确为止。

所以，要么：

while (password != PASSWORD) and (ALLOWED > 0):

或者：

    if ALLOWED == 0:
                print("You have been locked out")
                break

Answer 3

条件密码！= PASSWORD不足以退出循环（仅当您输入正确的密码时才会退出循环）。同时添加条件while（密码！= PASSWORD和ALLOWED＆gt; 0）

Answer 4

将print("You have been locked out")更改为sys.exit("You have been locked out")（或以其他方式退出main）。请务必import sys使用sys.exit。

Answer 5

您的while循环需要正确的密码才能完成，并且没有其他方法可以退出循环。我建议一个休息声明：

def main():
    PASSWORD = "apple"
    ALLOWED = 3

    password = input("Enter the password: ")
    while password != PASSWORD :
        ALLOWED = ALLOWED - 1
        print("Wrong. You have", ALLOWED, "guesses left")

        if ALLOWED == 0:
            print("You have been locked out")
            break
        password = input("Enter again ")

    print("You have successfully logged into the system")

如果您的计划需要安全，您可能需要做更多研究。

Answer 6

管理使它工作，但只是检查是否允许== 0，如果它确实打印“你被锁定”，如果允许＆lt; = 0那么它将不允许你继续前进。

def main():
    PASSWORD = "apple"
    ALLOWED = 3

    password = input("Enter the password: ")
    while password != PASSWORD or ALLOWED <= 0:
        ALLOWED = ALLOWED - 1
        if ALLOWED > 0: print("Wrong. You have", ALLOWED, "guesses left")
        if ALLOWED == 0: print("You have been locked out") 
        if ALLOWED < 0:
                    print("You have been locked out")
        password = input("Enter again ")            


    print("You have successfully logged into the system")



main()

还写了一个不同的版本，在我看来似乎更容易

def main():

    USERNAME = "admin"
    PASSWORD = "root"
    ATTEMPTS = 3
    while ATTEMPTS >= 1:
        print("You have",ATTEMPTS,"attempts left")
        if ATTEMPTS == 0:
            break
        user = input("Please enter your username:")
        password = input("Now enter your password:")
        if user == USERNAME and password == PASSWORD:
            print("\nYou have successfully logged into the system")
            return
        else:
            print("\nThis user name or password does not exist\n")
            ATTEMPTS -= 1
    print("you have been locked out.")

main()

我如何修复我的while循环

6 个答案: