python - 如何缩短这个替换密码？

Question

The input string will consist of only alphabetic characters. The function should return a string where all characters have been moved "up" two spots in the alphabet.

For example:

• "a" will become "c"
• "z" will become "b"

我写了这段代码，但我认为它太长了。我怎样才能让它更短、更好？

def encrypt_message(strings: str) -> str:
    our_al = ["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']
    new_s = ""
    for character in strings:
        index = our_al.index(character)
        if index <= 23:
            index += 2
            new_s += our_al[index]
        elif index == 24:
            new_s += our_al[0]
        elif index == 25:
            new_s += our_al[1]

    return new_s


print(encrypt_message("abc"))
print(encrypt_message("xyz"))
print(encrypt_message(""))

Answer 1

一些实用程序会很有用。如果您重复使用此函数，您并不总是希望迭代字符来查找索引，因此需要查找 dict。

from string import ascii_lowercase as al

index = {c: i for i, c in enumerate(al)}

def encrypt_message(s: str) -> str:
    return ''.join(al[(index[c] + 2) % 26] for c in s)

>>> encrypt_message('xyz')
'zab'