Translates letters and punctuation to and from morse code

translate_morse.py

ltom = {
        "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" : "--..",
        " " : "/",
        "." : ".-.-.-",
        "," : "--..--",
        ":" : "---...",
        "?" : "..--..",
        "'" : ".----.",
        "-" : "-....-",
        "/" : "-..-.",
        "@" : ".--.-.",
        "=" : "-...-"
    }

mtol = dict((v,k) for (k,v) in ltom.items())

def translate_mtol(morse):
    # Translate morse to letters
    translated = ''
    for seq in morse.split(' '):
        translated += mtol[seq]
    return translated

def translate_ltom(letters):
    # That's right, letters to morse
    translated = ''
    for letter in letters[:-1]:
        translated += ltom[letter] + ' '
    translated += ltom[letters[-1]]
    return translated

if __name__ == "__main__":
    test_string = 'SOS BITCHES'
    a = translate_ltom(test_string)
    b = translate_mtol(a)

    assert(test_string == b)
    print("See, it even works")