python - 凯撒密码 仅加密一个字母而不是整个字符串

Question

所以我正在制作一个简单的凯撒密码用于练习，但我无法让它破译整个字符串，只能破译单个字母。

symbol_add 是有问题的函数。

代码如下:

import re

alphabet = "abcdefghijklmnopqrstuvwxyz"

def cleanIt(clean):
    global alphabet
    s = re.sub('[^a-z]+', '?', str(clean))
    return s

def symbol_add(symbol, key):
    encryptedMsg = ""
    for x in symbol:
        position = alphabet.find(x)
        newPosition = (position + key) % 26
        newLetter = alphabet[nyPosisjon]

    encryptedMsg += nyBokstav
    return encryptedMsg

def cipher(data,key):
    text = ""
    if data in alphabet:
        text += symbol_add(symbol=data,key=key)
        return text

def main():
    try:
        msg = (input("Write the message you would like to encrypt\n"))
        key = int(input("which key would you like to use?\n"))
        cleanIt(clean=msg)
        print(cipher(data=msg, key=key))
    except ValueError:
        print("Write a number!")

main()

我确信解决方案非常简单，仍在学习中。

任何有关如何解决此问题的帮助将不胜感激!

Answer 1

import re

alphabet = "abcdefghijklmnopqrstuvwxyz"

def cleanIt(clean):
    global alphabet
    s = re.sub('[^a-z]+', '?', str(clean))
    return s

def symbol_add(symbol, key):
    position = alphabet.find(symbol)
    newPosition = (position + key) % 26
    newLetter = alphabet[newPosition]
    return newLetter

def cipher(data,key):
    text = ""
    for letter in data:
        if letter in alphabet:
            text += symbol_add(symbol=letter,key=key)
    return text

def main():
    try:
        msg = (input("Write the message you would like to encrypt\n"))
        key = int(input("which key would you like to use?\n"))
        # Note: you need to assign msg to be equal to cleanIt(clean=msg). 
        #       Just calling cleanIt(clean=msg) won't work, as strings 
        #       are immutable in Python
        msg = cleanIt(clean=msg)
        print(cipher(data=msg, key=key))
    except ValueError:
        print("Write a number!")

main()

主要变化是:

• for loop已移自 symbol_add至cipher ，这样symbol_add每个角色都会被调用
• 在 main() :cleanIt(clean=msg) -> msg = cleanIt(clean=msg) ;原因是Python中的字符串是不可变的，这意味着你需要重新分配变量msg实质上指向新字符串。

此代码的输出:

Write the message you would like to encrypt
test
which key would you like to use?
1
uftu

此外，尝试坚持单一命名约定；你有一个遵循 camelCase 的函数( cleanIt ) 以及随后的另一个 snake_case (symbol_add)。尝试以相同的方式命名所有函数。 (Python 中的约定是使用 snake_case 表示函数)