为什么我得到 `none` 作为输出？

Question

我正在做作业的凯撒密码加密代码。我想我输入了我需要写的所有内容。但是我确实有一个问题。

我在代码中得到 none：

def fancy_caesar(message, keyword, true_false_statement):
    count = 0
    while count == 0:
        true_false_statement = str(input("Type True if you want to encrypt.\nType false if you want to decrypt: "))
        if true_false_statement == 'true' or true_false_statement == 'True' or true_false_statement == 't' or true_false_statement == 'T':
            count = count + 1
        elif true_false_statement == 'false' or true_false_statement == 'False' or true_false_statement == 'F' or true_false_statement == 'f':
            count = count + 1
        else:
            print('None')
    alphabet = 'abcdefghijklmnopqrstuvwxyz'
    translated_message = ""
    keyword_index = 0

    for character in message:
        if character in alphabet:
            number = alphabet.find(character)
            if true_false_statement == 'true' or true_false_statement == 'True' or true_false_statement == 't' or true_false_statement == 'T':
                number = number + (ord(keyword[keyword_index]) - ord('a'))
            elif true_false_statement == 'false' or true_false_statement == 'False' or true_false_statement == 'F' or true_false_statement == 'f':
                number = number - (ord(keyword[keyword_index])) - ord('a')
            keyword_index += 1
            keyword_index = keyword_index % len(keyword)

            if number >= len(alphabet):
                number = number - len(alphabet)
            elif number < 0:
                number = number + len(alphabet)
            translated_message = translated_message + alphabet[number]
        else:
            translated_message = translated_message + character
            return translated_message

def main():
    message = input("Enter string you want to encrypt/decrypt: ")
    keyword = input('Keyword for encryption: ')            
    true_false_statement = ''
    translated_message = fancy_caesar(message, keyword,true_false_statement)
    print(translated_message)

main()

当我输入 message 输入 'sloth,' 时，我得到 none 而不是 'tlruh'。

有什么办法可以解决这个问题？

Answer 1

这是因为你在else块中添加了return translated_message（def main()上面的语句）。

移动语句与for语句对齐，你会得到想要的输出。

为什么我得到 `none` 作为输出？

Why am I getting `none` as the output?

python

encryption