Question

我尝试在Python中创建一个应用程序，让用户创建一个密码，然后让他们验证它。显然我必须创建一个循环，以便当用户输入不匹配的密码时，他们必须再次尝试。我对循环不太熟悉，所以这就是我得到的。我如何使这项工作？

这是代码：

password = raw_input ("Create a password: ")
passwordv = raw_input ("Retype your password: ")
a = ("Passwords don't match!  Please try again!: ")
b = ("Congrats, you have created a password")

def password():
    if password == passwordv :
        print ("Congrats, you have created a password")
    else :
        print (a)
    return password
    return passwordv
while password !=passwordv:
    print (a)

这是另一组试图做同样事情的代码：

password = raw_input('Create a password: ')
passwordv = raw_input('Veryify your password: ')

while (password != passwordv):
    print raw_input('Passwords do not match, try again: ')
    if (password == passwordv) :
        print ('Password set')
        break

Answer 1

您测试密码是否匹配的条件包含在循环中，该循环检查它们是否匹配 - 因此，它永远不会运行。

请改为尝试：

password = raw_input('Create a password: ')
passwordv = raw_input('Verify your password: ')

while (password != passwordv):
    print raw_input('Passwords do not match, try again. ')
    password = raw_input('Create a password: ')
    passwordv = raw_input('Verify your password: ')
    continue

print ('Password set')

请注意，如果密码不匹配，那么只应运行的代码包含在while循环中。

Answer 2

这里你需要的是一个N次半循环＆＃34;。为避免重复代码（由DRY原则引导），您可以考虑编写一个函数来获取密码。以下可能有效：

def get_passwords():
    password = raw_input('Create a password: ')
    passwordv = raw_input('Veryify your password: ')
    return password, passwordv

pw1, pw2 = get_passwords()
while pw1 != pw2:
    print "Sorry, passwords do not match"
    pw1, pw2 = get_passwords()

如果原始密码匹配，则根本不会输入循环。否则它会重复，直到它们为止。

Answer 3

password=raw_input('Enter password: \t\t\t')
passwordv=raw_input('Enter password again to verify:  \t')

if password == passwordv:
    print "\ncongratz you have created password"
else:
    print "\nPlease try again...!"

while password != passwordv:
    password=raw_input("Enter password: \t\t\t")
    passwordv=raw_input("Enter password again to verify:  \t")

    if password == passwordv:
        print"\ncongratz you have created password"
    else:
        print"\nPlease try again...!"

我知道这个很长，只是为了基本的理解

Answer 4

其他答案提供将执行您想要的代码。我认为告诉你更多你提供的代码有什么问题可能会很有趣，因为问题更多的是你对事物运作方式的理解。

第一次尝试：变量和函数具有相同的名称

# Here you define your password variable as a string
password = raw_input ("Create a password: ")
[...]

# And then you reassign it here: it contains now the address of that function! 
def password():
    [...]


# Now you're comparing a function to a string: they'll never be equal
while password !=passwordv:
    [...]

这可以通过更改你的功能名称来避免这种情况（这种情况从未被调用过，因此我不确定你想做什么，但我认为你可能会觉得这很有趣）。进一步阅读：Python: function and variable with same name

第二次尝试：变量的值保持不变

password = raw_input('Create a password: ')
passwordv = raw_input('Veryify your password: ')

# At this point, if the test is true, you'll reach the end of the code without
# displaying the 'Password set' message you wanted
while (password != passwordv):
    # This only prints a message
    print raw_input('Passwords do not match, try again: ')
    # The condition below can never be true: you just tested that they were
    # different but did nothing to give them new values!
    if (password == passwordv) :
        print ('Password set')
        break

解决问题的方法是其他答案提供的方法：将你的信息从循环中取出（离开循环意味着你的条件得到满足）;确保你在循环中做了一些事情，以确保下一个测试与前一个测试不同（否则，你将最终反复测试相同的值）;为了避免在循环内部破坏，在循环外设置值，然后在初始测试失败的情况下在循环内获取新值。

Answer 5

这是一个想法：首先定义这些：

MinPass = 6
MaxPass = 12

然后这个：

print ("Now, lets try with a password. Please enter one here")
EnteredPassword = input("Password: ")
while len(EnteredPassword) < MinPass:
    print ("That password is too small. Please try again")
    EnteredPassword = input("Password: ")
while len(EnteredPassword) > MaxPass:
    print ("That password is too long, please try again")
    EnteredPassword = input("Password: ")

希望这有帮助！

密码检查器循环不起作用

5 个答案:

第一次尝试：变量和函数具有相同的名称

第二次尝试：变量的值保持不变