找到簡單的方法來翻譯基於密鑰的字符串

Question

基本上我有一個函數，將非常簡單地加密一條消息。

def encrypt(message): 
    alphabet = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"] 
    key = ["4","x","z","@","%","b","j","q","(","ƒ","¥","µ","˚","nå","ø","π","å","œ","¢","∞","∫","µ","≈","`","¬","…"] 
    new_message = "" 
    for x in range(0,len(message)): 
     new_message = message.replace(message[x],key.index[alphabet.index(message[x])]) 
    return new_message 

print(encrypt(input("What would you like to encrypt").lower())) 

這應該採信，並在列表鍵相同的索引字符替換它，但我得到的錯誤：

TypeError: 'builtin_function_or_method' object is not subscriptable 

Answer 1

最後一個用例爲str.translate！請注意，key中的一個條目由兩個字符組成。如果這是有意的，並且您想用兩個字符替換單個字符，則可以手動創建翻譯表。

table = dict(zip(map(ord, alphabet), key)) 

Answer 2

key.index()需要一個值，並返回其索引，並用它()不[]所以你需要修復這一行：

new_message = message.replace(message[x],key.index[alphabet.index(message[x])]) 

到：

new_message = message.replace(message[x],key[alphabet.index(message[x])]) 

這將採取字母索引並使用它訪問key列表並獲取該索引處的值以將其替換爲原始字母。

編輯： 一個更好的辦法來做到這一點是使用dictionary，構建一個新的字符串isntead，以避免重複replace()在string

dic = {'a': '4', 'b': 'x', 'c': 'z' ...} 
new_message = '' 
for x in message: 
    new_message += dic[x] 
return new_message 

Answer 3

我建議使用一箇中間dict創建alphabet列表項的映射與key列表項：

>>> alphabet = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"] 
>>> key = ["4","x","z","@","%","b","j","q","(","ƒ","¥","µ","˚","nå","ø","π","å","œ","¢","∞","∫","µ","≈","`","¬","…"] 

# Your `dict` object with the mapping between both the list 
>>> encryption_dict = dict(zip(alphabet, key)) 

然後使用上面的字典str.join(...)來轉換你的字符串。例如：

>>> my_str = 'stackoverflow' 

# Transform the string using the `dict` and join the chars to form single string   
>>> new_str = ''.join(encryption_dict.get(s, s) for s in my_str) 
#           ^
#  to return same character if not present in alphabet list 

>>> print(new_str) 
¢∞4z¥øµ%œbµø≈