凯撒密码翻译错误

Question

凯撒密码偏移量为 21，字母表为“abcdefghijklmnopqrstuvwxyz0123456789”。

例如“Xvzcvb”应该等于“Caesar”，但输出却是“CaeNaM”

ALPHABET = "abcdefghijklmnopqrstuvwxyz0123456789."

def decrpytstr(message):
    #declare variables
    newString = str()
    ALPHABET = int()
    oneLetter = str()
    newAlphabetValue = int()
    #loop to assign new alphabet value
    for index in range(0, len(message)):
        oneLetter = message[index]
        ALPHABET = ord(oneLetter)

        #assinging new alphabet value
        newAlphabetValue = ALPHABET - 21
        #creating the new string
        newString = newString + chr(newAlphabetValue)
    
    return newString


def main():
    message = input("Enter text: ")
    decrpytstr(message)
    newString = decrpytstr(message)
    print(newString)
    input("Press ENTER to exit")
main()

Answer 1

https://www.asciitable.com/ 正如我看到的 ascii table，b 98 的值将是 M 77 递减 21。我猜你必须分别处理大写和小写。

[已编辑]我不太明白你想达到什么目的，但是这个怎么样？

ALPHABET = "abcdefghijklmnopqrstuvwxyz"

def decrpytstr(message):
    new_string = ""
    for i in range(len(message)):
        character = message[i]
        new_character = ALPHABET[ALPHABET.find(character) - 21 % 26]
        new_string = new_string + new_character
    return new_string


def main():
    message = input("Enter text: ")
    decrpytstr(message)
    newString = decrpytstr(message)
    print(newString)
    input("Press ENTER to exit")
main()

Enter text: xvznvm
caesar
Press ENTER to exit

Answer 2

有几个问题

您实际上并没有使用原来的字母表值
您没有考虑大写字符
我们需要环绕，这样当我们减去神奇的 21 步时，我们总能找到字母表中的东西

更正这些给我们这样的东西...

ALPHABET = "abcdefghijklmnopqrstuvwxyz0123456789."

def decrpytstr(message):
    newString = ''
    #loop to assign new alphabet value
    for index in range(0, len(message)):
        oneLetter = message[index]

        #assinging new alphabet value
        newAlphabetValue = (ALPHABET.find(oneLetter.lower()) - 21) % len(ALPHABET) + (ord('A') if oneLetter.isupper() else ord('a'))
        #creating the new string
        newString = newString + chr(newAlphabetValue)
    
    return newString


def main():
    message = input("Enter text: ")
    decrpytstr(message)
    newString = decrpytstr(message)
    print(newString)
    input("Press ENTER to exit")
main()

凯撒密码翻译错误

Caesar Cipher Translating Incorrectly

python

caesar-cipher