Functions

Caesar's Code

letters = "А Б В Г Д Е Ё Ж З И Й К Л М Н О П Р С Т У Ф Х Ц Ч Ш Щ Ъ Ы Ь Э Ю Я"
divided_letters = letters.split()


def encrypt(s, k):
    mod_letters = []
    for w in s.upper():
        if w in divided_letters:
            index = divided_letters.index(w) + k
            if index > len(divided_letters) or index < 0:
                index = index % len(divided_letters)
            else:
                pass
            mod_letters.append(divided_letters[index])
            normal_letters = ''.join(mod_letters)
        else:
            mod_letters.append(w)
            normal_letters = ''.join(mod_letters)
    return str(normal_letters)


message = "Привет world!"
encrypted_message = encrypt(message, 55)
decrypted_message = encrypt(encrypted_message, -55)
print(encrypted_message)
print(decrypted_message)