Encrypt and Decrypt Caesar Ciphers

caesar_cipher.py

def cipher(string: str, offset: int) -> str:
    result = ''
    for char in string:
        if 'a' <= char <= 'z':
            start, end = 'a', 'z'
        elif 'A' <= char <= 'Z':
            start, end = 'A', 'Z'
        else:
            start, end = char, char
        
        result += chr(
            (ord(char) - ord(start) + offset)
            % (ord(end) - ord(start) + 1)
            + ord(start)
        )
    return result


def decrypt_all(string: str) -> list[str]:
    return [cipher(string, i) for i in range(26)]


# >>> print(cipher('and', 3))
# dqg
# >>> print(*decrypt_all('and'), sep='\n')
# and
# boe
# cpf
# ...