class CaesarCypherClass:
    """
    恺撒密码，提供以恺撒密码方法进行加密及解密的方法，加密方法使用CaesarEncode()函数，解密方法使用CaesarDecode()函数
    """

    def __init__(self, *args, **kwargs):
        pass

    @staticmethod
    def caesar_encode(s):
        """
        恺撒密码加密方法，需要提供需要加密的明文。
        """
        s_encode = ''
        for c in s:
            if 'a' <= c <= 'z':
                s_encode += chr(ord('a') + (ord(c) - ord('a') + 3) % 26)
            elif 'A' <= c <= 'Z':
                s_encode += chr(ord('A') + (ord(c) - ord('A') + 3) % 26)
            elif 0x4E00 <= ord(c) <= 0x9FA5:
                s_encode += chr(ord(c) + 3)
            elif '0' <= c <= '9':
                s_encode += chr(ord('0') + (ord(c) - ord('0') + 3) % 10)
            else:
                s_encode += c
        return s_encode

    @staticmethod
    def caesar_decode(s):
        """
        恺撒密码解密方法，需要提供需要解密的密文。
        """
        s_decode = ''
        for c in s:
            if 'a' <= c <= 'z':
                s_decode += chr(ord('a') + (ord(c) - ord('a') - 3) % 26)
            elif 'A' <= c <= 'Z':
                s_decode += chr(ord('A') + (ord(c) - ord('A') - 3) % 26)
            elif 0x4E00 <= ord(c) <= 0x9FA5:
                s_decode += chr(ord(c) - 3)
            elif '0' <= c <= '9':
                s_decode += chr(ord('0') + (ord(c) - ord('0') - 3) % 10)
            else:
                s_decode += c
        return s_decode


class Base64CypherClass:
    """
    Base64的加解密算法，最简单的加密方式，可加密短的文字、小图片、小文件，图片文件大小不宜超过10M
    """