game of life in python

game-of-life.py

from sets import Set


class Game:
    def __init__(self, state):
        self.state = state

    def next(self):
        new_state = Set()
        for cell in state:
            # compute next state for this cell
            if 2 <= self.count_neighbours(cell) <= 3:
                new_state.add(cell)
            # check if dead neighbours alive next?
            x, y = cell
            for i in range(x-1, x+2):
                for j in range(y-1, y+2):
                    if (i != x or j != y) and (i, j) in state:
                        pass
                    else:
                        if self.count_neighbours((i, j)) == 3:
                            new_state.add((i, j))

        self.state = new_state

    def count_neighbours(self, cell):
        live_neighbour_count = 0
        x, y = cell
        for i in range(x-1, x+2):
            for j in range(y-1, y+2):
                if (i != x or j != y) and (i, j) in state:
                    live_neighbour_count = live_neighbour_count + 1
        return live_neighbour_count


state = Set([(0, 0), (0, 1), (0, 2)])
g = Game(state)
g.next()

print g.state