Vigenere_Cipher_Helper.py

import unittest

class VigenereCipher(object):
    def __init__(self, key, alphabet):
        self.key = key
        self.alphabet = alphabet

    def encode(self, text):
        result = ""
        key_len = len(self.key)
        alphabet_len = len(self.alphabet)
        key_index = 0
        
        for char in text:
            if char in self.alphabet:
                char_index = self.alphabet.index(char)
                key_char = self.key[key_index % key_len]
                key_val = self.alphabet.index(key_char)
                new_index = (char_index + key_val) % alphabet_len
                result += self.alphabet[new_index]
            else:
                result += char
            key_index += 1
        
        return result

    def decode(self, text):
        result = ""
        key_len = len(self.key)
        alphabet_len = len(self.alphabet)
        key_index = 0
        
        for char in text:
            if char in self.alphabet:
                char_index = self.alphabet.index(char)
                key_char = self.key[key_index % key_len]
                key_val = self.alphabet.index(key_char)
                new_index = (char_index - key_val) % alphabet_len
                result += self.alphabet[new_index]
            else:
                result += char
            key_index += 1
        
        return result


class TestVigenereCipher(unittest.TestCase):
    def setUp(self):
        abc = "abcdefghijklmnopqrstuvwxyz"
        key = "password"
        self.cipher = VigenereCipher(key, abc)

    def test_sample_cases(self):
        self.assertEqual(self.cipher.encode('codewars'), 'rovwsoiv', "Test de codificación 'codewars'")
        self.assertEqual(self.cipher.decode('rovwsoiv'), 'codewars', "Test de decodificación 'rovwsoiv'")
        self.assertEqual(self.cipher.encode('waffles'), 'laxxhsj', "Test de codificación 'waffles'")
        self.assertEqual(self.cipher.decode('laxxhsj'), 'waffles', "Test de decodificación 'laxxhsj'")
        self.assertEqual(self.cipher.encode('CODEWARS'), 'CODEWARS', "Test de codificación 'CODEWARS'")
        self.assertEqual(self.cipher.decode('CODEWARS'), 'CODEWARS', "Test de decodificación 'CODEWARS'")
        self.assertEqual(self.cipher.encode("it's a shift cipher!"), "xt'k o vwixl qzswej!", "Test con espacios y puntuación")
        self.assertEqual(self.cipher.decode("xt'k o vwixl qzswej!"), "it's a shift cipher!", "Test de decodificación con espacios y puntuación")


if __name__ == '__main__':
    unittest.main(verbosity=2)