程序未返回预期结果

Question

因此，我编写了一个程序，使用凯撒平移算法对消息进行加密。这是代码：

MAX_KEY_SIZE = 26

def getMode():
    while True:
        print('Do you wish to encrypt or decrypt a message?')
        mode = input().lower()
        if mode in 'encrypt e decrypt d'.split():
            return mode
        else:
            print('Enter either "encrypt" or "e" or "decrypt" or "d".')

def getMessage():
    print('Enter your message:')
    return input()

def getKey():
    key = 0
    while True:
        print('Enter the value you want your message to be shifted by. You can choose anything from 1 to 26.')
        key = int(input())
        if (key >= 1 and key <= MAX_KEY_SIZE):
            return key

def getTranslatedMessage(mode, message, key):
    if mode[0] == 'd':
        key = -key
        translated = ''

    for symbol in message:
        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

        translated += chr(num)
    else:
        translated += symbol
        return translated

mode = getMode()
message = getMessage()
key = getKey()
print('Your translated text is:')
print(getTranslatedMessage(mode, message, key))

这是在Visual Studio Code中运行它会发生的事情：

“您是否希望加密或解密邮件？加密

输入您的消息：银

输入您要转移其消息的值。您可以选择1到26之间的任何值。3

您翻译的文本是：无“

问题在于，无论输入什么消息进行加密，我总是得到相同的答案：'none'，而不是加密的消息。

有人对我该如何解决有任何想法吗？

Answer 1

我相信您的问题完全在您的缩进中，应该在您最初的if语句中包含某些部分，而不是。

使用python时，您必须非常小心缩进，因为没有括号可以控制条件。

MAX_KEY_SIZE = 26

def getMode():
    while True:
        print('Do you wish to encrypt or decrypt a message?')
        mode = input().lower()
        if mode in 'encrypt e decrypt d'.split():
            return mode
        else:
            print('Enter either "encrypt" or "e" or "decrypt" or "d".')

def getMessage():
    print('Enter your message:')
    return input()

def getKey():
    key = 0
    while True:
        print('Enter the value you want your message to be shifted by. You can choose anything from 1 to 26.')
        key = int(input())
        if (key >= 1 and key <= MAX_KEY_SIZE):
            return key

def getTranslatedMessage(mode, message, key):
    translated = ''

    if mode[0] == 'd':
        key = -key

    for symbol in message:
        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

            translated += chr(num)
        else:
            translated += symbol
    return translated

mode = getMode()
message = getMessage()
key = getKey()
print('Your translated text is:')
print(getTranslatedMessage(mode, message, key))