Conway's Game of Life

conways_game_of_life.py

def make_board(width, height):
    return [[0 for x in range(width)] for y in range(height)]

def print_board(board):
    for row in board:
        print ''.join([str(x) for x in row])

def neighbors(board, x, y):
    def coords(x, y):
        yield x - 1, y - 1
        yield x, y - 1
        yield x + 1, y -1
        yield x - 1, y
        yield x + 1, y
        yield x - 1, y + 1
        yield x, y + 1
        yield x + 1, y + 1
    for col, row in coords(x, y):
        if row >= 0 and row < len(board) and col >= 0 and col < len(board[row]):
            yield board[row][col]

def live_neighbors(board, x, y):
    return len(list(i for i in neighbors(board, x, y) if i))

board = make_board(25, 25)

board[1][1] = 1
board[1][2] = 1
board[2][1] = 1
board[2][2] = 1

board[3][3] = 1
board[3][4] = 1
board[4][3] = 1
board[4][4] = 1

for i in xrange(10):
    print_board(board)
    print

    new_board = make_board(25, 25)
    for row in xrange(len(board)):
        for col in xrange(len(board[row])):
            ln = live_neighbors(board, row, col)
            if board[row][col]:
                if ln < 2:
                    new_board[row][col] = 0
                elif ln == 2 or ln == 3:
                    new_board[row][col] = 1
                elif ln > 3:
                    new_board[row][col] = 0
            elif ln == 3:
                new_board[row][col] = 1
    board = new_board

    print_board(board)
    print