hangman_solver.py

def buildRegex(secret, knownLetters):
    regex = ''

    for letter in secret:
        if letter in knownLetters:
            regex += letter
        else:
            regex += '.'

    return regex

# "secret" is the secret word
# "dictionary" is the list of available words
def playGame(secret, dictionary):
    if secret not in dictionary:
        print('secret not in dictionary')
        return 0

    dictionary = list(filter(lambda x: len(x) == len(secret), dictionary))
      
    mistakes = 0
    alphabet = list('abcdefghijklmnopqrstuvwxyz')
    knownLetters = set()
    regex = buildRegex(secret, knownLetters)

    while True:
        # build probabilities
        probabilities = dict.fromkeys(alphabet, 0)

        for word in dictionary:

            # iterate over letters left in alphabet which are in word
            for letter in alphabet:
                if letter in word:
                    probabilities[letter] += 1


        # find letter with highest probability
        maxProb = 0
        guess = 'z'
        for letter in probabilities:
            if probabilities[letter] > maxProb:
                maxProb = probabilities[letter]
                guess = letter

        alphabet = list(filter(lambda x: x != guess))

        # guess the letter
        if guess in secret:
            knownLetters.add(guess)
            regex = buildRegex(secret, knownLetters)

            if not '.' in regex:
                return mistakes

            dictionary = list(filter(lambda x: re.match(regex, x), dictionary))

            if len(dictionary) == 1:
                return mistakes

        else:
            mistakes += 1
            dictionary = list(filter(lambda x: guess not in word, dictionary))