题解 | 字符串加解密

import sys


def encrypt(char):
    s = []
    for c in char:
        if c.isalpha():
            if c.islower():
                s.append(chr( (ord(c)-ord('a') + 1) % 26 + ord('A') ))
            else:
                s.append(chr( (ord(c) - ord('A') + 1) % 26 + ord('a')))
        elif c.isdigit():
            s.append(chr( (ord(c) - ord('0') + 1) % 10 + ord('0')))
        else:
            break
    return ''.join(s)

def decrypt(char):
    s = []
    for c in char:
        if c.isalpha():
            if c.islower():
                s.append(chr( (ord(c) - ord('a') -1) % 26 + ord('A')))
            else:
                s.append(chr( (ord(c) - ord('A') -1) % 26 + ord('a')))
        elif c.isdigit():
            s.append(chr( (ord(c) - ord('0') - 1) % 10 + ord('0')))
        else:
            break
    return ''.join(s)

if __name__ == "__main__":
    input_lines = sys.stdin.read().splitlines()
    s = input_lines[0]
    encrypted = encrypt(s)
    print(encrypted)
    decrypted = decrypt(input_lines[1])
    print(decrypted)