game_of_life.py

import time

def print_board(board):
    for row in board:
        for column in row:
            print(column),
        print("")
    print("- " * len(board[0]))

def count_neighbours(x, y, board):
    count = 0

    for _y in (y-1, y, y+1):
        for _x in (x-1, x, x+1):
            if _y == y and _x == x:
                continue

            if _y < 0 or _x < 0:
                continue

            if _y >= len(board) or _x >= len(board[0]):
                continue

            count += board[_y][_x]

    return count


def gol(x, y, board):
    """
    1. Any live cell with fewer than two live neighbours dies, as if caused by under-population.
    2. Any live cell with two or three live neighbours lives on to the next generation.
    3. Any live cell with more than three live neighbours dies, as if by overcrowding.
    4. Any dead cell with exactly three live neighbours becomes a live cell, as if by reproduction.
    """
    neighbours = count_neighbours(x, y, board) 

    if board[y][x]:
        if neighbours < 2:
            return 0
        elif neighbours <= 3:
            return 1
        else:
            return 0
    else:
        if neighbours == 3:
            return 1

    return 0

def next_step(board):
    return [[gol(x,y, board) for x in xrange(len(board[0])) ] for y in xrange(len(board))]

def main():
    board = [
            [0,0,0,0,0,0],
            [0,0,1,0,0,0],
            [1,0,1,0,0,0],
            [0,1,1,0,0,0],
            [0,0,0,0,0,0],
            [0,0,0,0,0,0],
            ]

    while True:
        print_board(board)
        new_board = next_step(board)
        if new_board == board:
            break

        board = new_board
        time.sleep(0.1)

main()