15 the game

fifteen.py

"""
A game where two players take turns choosing different numbers in
1, ..., 9 until one player has chosen three numbers that sum to 15,
thereby winning the game. If all numbers are chosen without any player
winning, the game is declared a tie.
"""

import itertools


class FifteenGame:

    def __init__(self):
        self.newGame()

    def newGame(self):
        self.activePlayer = 0    # Players are labelled 0 and 1
        self.numbers = [[], []]  # List containing each player's choices
        self.gameOver = False   # Has the game ended yet?
        self.winningSet = ()    # Contains a solution set if a player has won
        self.tie = False        # Is true if the game has ended in a tie

    def chooseNumber(self, n):
        if self.gameOver:
            raise RuntimeError("Game not in progress")
        if n not in range(1, 10):
            raise ValueError("Number should be integer between 1 and 9")
        if n in self.numbers[0] + self.numbers[1]:
            raise ValueError("Number already chosen by previous player")
        self.numbers[self.activePlayer].append(n)
        if not self.checkWinCondition():
            self.activePlayer = (self.activePlayer + 1) % 2  # Switch player

    def checkWinCondition(self):  # Checks if the game has ended
        if set(self.numbers[0] + self.numbers[1]) == set(range(1, 10)):
            self.gameOver = True
            self.tie = True
        for subset in list(itertools.combinations(self.numbers[self.activePlayer], 3)):
            if sum(subset) == 15:
                self.gameOver = True
                self.winningSet = subset
        return self.gameOver