Python 使用凯撒密码解密

我正在开发一个密码保护程序，我有一个用于加密的Caesar密码，它是：

#  The encryption key for the Caesar Cipher
encryptionKey = 16

#  Caesar Cipher Encryption
def passwordEncrypt (unencryptedMessage, key):

#  We will start with an empty string as our encryptedMessage
encryptedMessage = ''

#  For each symbol in the unencryptedMessage we will add an encrypted symbol 
into the encryptedMessage
    for symbol in unencryptedMessage:
        if symbol.isalpha():
            num = ord(symbol)
            num += key

            if symbol.isupper():
                if num > ord('Z'):
                    num -= 26
                elif num < ord('A'):
                    num += 26
            elif symbol.islower():
                if num > ord('z'):
                    num -= 26
                elif num < ord('a'):
                    num += 26

            encryptedMessage += chr(num)
        else:
            encryptedMessage += symbol

    return encryptedMessage

if choice == '2':  # Lookup a password
    print("Which website do you want to lookup the password for?")
    for keyvalue in passwords:
        print(keyvalue[0])
    passwordToLookup = input()

我给用户提供了一系列选择，选择2允许用户查找保存的密码，即：

#  The encryption key for the Caesar Cipher
encryptionKey = 16

#  Caesar Cipher Encryption
def passwordEncrypt (unencryptedMessage, key):

#  We will start with an empty string as our encryptedMessage
encryptedMessage = ''

#  For each symbol in the unencryptedMessage we will add an encrypted symbol 
into the encryptedMessage
    for symbol in unencryptedMessage:
        if symbol.isalpha():
            num = ord(symbol)
            num += key

            if symbol.isupper():
                if num > ord('Z'):
                    num -= 26
                elif num < ord('A'):
                    num += 26
            elif symbol.islower():
                if num > ord('z'):
                    num -= 26
                elif num < ord('a'):
                    num += 26

            encryptedMessage += chr(num)
        else:
            encryptedMessage += symbol

    return encryptedMessage

if choice == '2':  # Lookup a password
    print("Which website do you want to lookup the password for?")
    for keyvalue in passwords:
        print(keyvalue[0])
    passwordToLookup = input()

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密码保护程序对密码进行加密，但我需要它仅使用passwordEncrypt（）函数对密码进行解密

我的答案被删除了吗？我似乎在任何地方都找不到它，我几乎可以肯定我发布了它。要使用您的函数进行解密，只需传递

key

的负数，例如

-16

我的答案被删除了吗？我似乎在任何地方都找不到它，我几乎可以肯定我发布了它。要使用您的函数进行解密，只需传递

key

的负数，例如

-16