找不到基于键翻译字符串的简单方法

Question

基本上，我有一个可以非常简单地加密消息的函数。

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()))

这应该取字母并将其替换为列表键中具有相同索引的字符，但是我收到错误：

TypeError: 'builtin_function_or_method' object is not subscriptable

Answer 1

终于有了str.translate的用例！

def encrypt(message):
    alphabet = 'abcdefghijklmnopqrstuvwxyz'
    key = '4xz@%bjq(ƒ¥µ˚nåøπ圢∞∫µ≈`¬'
    table = str.maketrans(alphabet, key)

    return message.translate(table)

print(encrypt('asdsaewqeq')) # 4œ@œ4%µπ%π

请注意，key 中的一个条目由两个字符组成。如果这是故意的，并且您想用两个替换单个字符，那么您可以手动创建翻译表。

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

Answer 2

key.index() 接受一个值并返回它的索引，它使用() 而不是[] 所以你需要修复这一行：

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

到：

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

这将获取字母索引并使用它访问key 列表并获取该索引处的值以将其替换为原始字母。

编辑： 一个更好的方法是使用dictionary 并构造一个新的字符串，以避免在string 上出现双重replace()

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

Answer 3

我建议使用中间dict 来创建alphabet 列表项与key 列表项的映射：

>>> 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))

然后使用上面的字典和str.join(...) 来转换你的字符串。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≈