具有所需功能的Python Vigenere密碼

Question

我正在研究創建凱撒密碼和vigenere密碼的在線課程，但我們首先創建了兩個函數;一個用於查找字母變量中的字母位置，另一個用於將給定字符旋轉給定的時間量（我已經看到ord（）和chr（）更好地工作，但是該任務要求我們專注於更簡單的概念現在，我猜）。

我能夠得到凱撒函數的工作，但我不確定如何繼續使用vigenere密碼。我觀看了許多視頻並瀏覽了這個網站，但還沒有發現任何允許保留空格和非字母字符的內容。任何人都可以指出我如何開始vigenere功能的正確方向？

#Create function alphabet_position(letter) to turn letter into number 
#such as a=0 or e=4, using lowercase to make sure case doesnt matter. 
def alphabet_position(letter): 
    alphabet ="abcdefghijklmnopqrstuvwxyz" #Lists alphabet for a key 
    lower_letter = letter.lower() #Makes any input lowercase. 
    return alphabet.index(lower_letter) #Returns the position of input as a number. 

def rotate_character(char, rot): 
    alphabet = "abcdefghijklmnopqrstuvwxyz" 
    if char.isalpha(): 
     a = alphabet_position(char) 
     a = (a + rot) % 26   #needs modulo 
     a = (alphabet[a]) 
     if char.isupper(): 
      a = a.title() 
     return a 
    else: 
     return char 

def encrypt(text, rot): 
    list1 = "" 
    for char in text: 
     list1 += rotate_character(char, rot) 
    return list1 



def main(): 
    x = input("Type a message: ") 
    y = input("Rotate by: ") 
    #result = rotate_character(x, y) #Not needed once encrypt function works. 
    result = encrypt(x, y) 
    print (result) 

if __name__ == '__main__': 
    main() 

Answer 1

以下我的評論;使用所有的字母表：

from string import ascii_letters, digits, punctuation, whitespace 

ALPHABET = ascii_letters + digits 
STATIC_ALPHABET = punctuation + whitespace 

# minor speedup 
ALPHA_INDEX = {a: i for i, a in enumerate(ALPHABET)} 
STATIC_ALPHABET_SET = set(STATIC_ALPHABET) 
MOD = len(ALPHABET) 

def encrypt(char, key): 
    if char in STATIC_ALPHABET_SET: 
     return char 
    else: 
     return ALPHABET[(ALPHA_INDEX[char] + key) % MOD] 

def decrypt(char, key): 
    if char in STATIC_ALPHABET_SET: 
     return char 
    else: 
     return ALPHABET[(ALPHA_INDEX[char] + MOD - key) % MOD] 

key = 17 
plain = 'Hello World!' 
enc = ''.join(encrypt(char, key) for char in plain) 
print(enc) # YvCCF dFICu! 
dec = ''.join(decrypt(char, key) for char in enc) 
print(dec) # Hello World!