Conway's Game of life from 2012 Pycon

conway.py

"""
Based on 2012 Pycon Talk: "Stop Writing Classes" by Jack Diederich
- https://us.pycon.org/2012/schedule/presentation/352/

Noted rules from Wikipedia: https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life

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 over-population.
4. Any dead cell with exactly three live neighbours becomes a live cell, as if by reproduction.
"""
import itertools


def neighbors(point):
    x, y = point
    yield x + 1, y
    yield x - 1, y
    yield x, y + 1
    yield x, y - 1
    yield x + 1, y + 1
    yield x + 1, y - 1
    yield x - 1, y + 1
    yield x - 1, y - 1


def advance(board):
    newstate = set()
    recalc = board | set(itertools.chain(*map(neighbors, board)))
    for point in recalc:
        count = sum((neigh in board) for neigh in neighbors(point))
        if count == 3 or (count == 2 and point in board):
            newstate.add(point)
    display(newstate)
    return newstate


def display(board):
    top_x = max(board, key=lambda p: p[0])[0]
    top_y = max(board, key=lambda p: p[1])[1]
    bot_x = min(board, key=lambda p: p[0])[0]
    bot_y = min(board, key=lambda p: p[1])[1]
    dx = top_x - bot_x + 1
    dy = top_y - bot_y + 1
    grid = [[' ' for _ in range(dy)] for _ in range(dx)]
    for cell in board:
        grid[top_x-cell[0]][top_y-cell[1]] = 'x'
    divider = '|--' + ('-+--' * (dy - 1)) + '-|\n'
    for row in grid:
        print divider + '| ' + ' | '.join(row) + ' |'
    print divider


glider = set([(0, 0), (1, 0), (2, 0), (0, 1), (1, 2)])
display(glider)
for i in range(1000):
    glider = advance(glider)