[2018-03-26] Challenge #355 [Easy] Alphabet Cipher

import string
alphabet = string.ascii_lowercase
substitution = {letter: {let: alphabet[alphabet.index(let) - (26 - alphabet.index(letter))] for let in alphabet} for
                letter in alphabet}
substitution_reverse = {letter: {alphabet[alphabet.index(let) - (26 - alphabet.index(letter))]: let for let in alphabet}
                        for letter in alphabet}


def encode(keyword, message):
    result = ""
    for index in range(len(message)):
        result += substitution[keyword[index % len(keyword)]][message[index]]
    print(result)


def decode(keyword, message):
    result = ""
    for index in range(len(message)):
        result += substitution_reverse[keyword[index % len(keyword)]][message[index]]
    print(result)


encode('snitch', 'thepackagehasbeendelivered')
encode('bond', 'theredfoxtrotsquietlyatmidnight')
encode('train', 'murderontheorientexpress')
encode('garden', 'themolessnuckintothegardenlastnight')
decode('cloak', 'klatrgafedvtssdwywcyty')
decode('python', 'pjphmfamhrcaifxifvvfmzwqtmyswst')
decode('moore', 'rcfpsgfspiecbcc')