letter_to_morse = {'a':'.-', 'b':'-...', 'c':'-.-.', 'd':'-..', 'e':'.', 'f':'..-.', 'g':'--.', 'h':'....', 'i':'..', 'j':'.---', 'k':'-.-', 'l':'.-..', 'm':'--', 'n':'-.', 'o':'---', 'p':'.--.', 'q':'--.-', 'r':'.-.', 's':'...', 't':'-','u':'..-', 'v':'...-', 'w':'.--', 'x':'-..-', 'y':'-.--', 'z':'--..','0':'-----', '1':'.----', '2':'..---', '3':'...--', '4':'....-','5':'.....', '6':'-....', '7':'--...', '8':'---..', '9':'----.', ' ':'/'}def encode(message): morse = []for letter in message: letter = letter.lower() morse_letter = letter_to_morse[letter] morse.append(morse_letter) morse_message =" ".join(morse)return morse_message# We need to invert the dictionary. This will create a dictionary# that can go from the morse back to the lettermorse_to_letter = {}for letter in letter_to_morse: morse = letter_to_morse[letter] morse_to_letter[morse] = letterdef decode(message): english = []# Now we cannot read by letter. We know that morse letters are# separated by a space, so we split the morse string by spaces morse_letters = message.split(" ")for letter in morse_letters: english_letter = morse_to_letter[letter] english.append(english_letter)# Rejoin, but now we don't need to add any spaces english_message ="".join(english)return english_message