life-v0.7_class_board.py

#!/usr/bin/python3

"""
Author: Leo Vidarte <http://nerdlabs.com.ar>

This is free software,
you can redistribute it and/or modify it
under the terms of the GPL version 3
as published by the Free Software Foundation.

"""

"""
Las transiciones dependen del número de células vecinas vivas:

  * Una célula muerta con exactamente 3 células vecinas vivas "nace"
    (al turno siguiente estará viva).
  * Una célula viva con 2 ó 3 células vecinas vivas sigue viva.
  * En otro caso muere o permanece muerta (por "soledad" o "superpoblación").

"""


class Board:

    DEAD  = 0
    ALIVE = 1

    def __init__(self, width=8, height=8):
        self._width  = width
        self._height = height
        self.set(self._get_empty_board_list())

    def set(self, board_list):
        self._board_list  = [row[:] for row in board_list] # deep copy
        self._width       = len(board_list[0])
        self._height      = len(board_list)

    def _get_empty_board_list(self):
        return [[self.DEAD] * self._width for _ in range(self._height)]

    def get(self):
        return self._board_list

    def size(self):
        return (self._width, self._height)

    def count_neighbors_alive(self, x, y):
        x_center, y_center = x, y

        x_left  = x_center-1 if x_center-1 >= 0           else self._width-1
        x_right = x_center+1 if x_center+1 < self._width  else 0
        y_up    = y_center-1 if y_center-1 >= 0           else self._height-1
        y_down  = y_center+1 if y_center+1 < self._height else 0

        return (self._board_list[y_up][x_left],
                self._board_list[y_up][x_center],
                self._board_list[y_up][x_right],
                self._board_list[y_center][x_left],
                self._board_list[y_center][x_right],
                self._board_list[y_down][x_left],
                self._board_list[y_down][x_center],
                self._board_list[y_down][x_right]).count(self.ALIVE)

    def get_next_cell_state(self, cell_state, neighbors_alive):
        if (cell_state == self.DEAD and neighbors_alive == 3) or \
           (cell_state == self.ALIVE and neighbors_alive in (2, 3)):
            return self.ALIVE
        else:
            return self.DEAD

    def tick(self):
        board_list = self._get_empty_board_list()
        for x in range(self._width):
            for y in range(self._height):
                cell_state = self._board_list[y][x]
                neighbors_alive = self.count_neighbors_alive(x, y)
                args = (cell_state, neighbors_alive)
                board_list[y][x] = self.get_next_cell_state(*args)
        self._board_list = board_list


if __name__ == '__main__':

    from time import sleep

    # Glider
    board_list = [
        [0, 0, 0, 0, 0, 0, 0, 0],
        [0, 0, 0, 1, 0, 0, 0, 0],
        [0, 0, 0, 0, 1, 0, 0, 0],
        [0, 0, 1, 1, 1, 0, 0, 0],
        [0, 0, 0, 0, 0, 0, 0, 0],
        [0, 0, 0, 0, 0, 0, 0, 0],
        [0, 0, 0, 0, 0, 0, 0, 0],
        [0, 0, 0, 0, 0, 0, 0, 0],
    ]

    board = Board()
    board.set(board_list)

    def print_board(board_list):
        for row in board_list:
            print(' '.join(['.' if col == Board.DEAD else '#' for col in row]))

    for i in range(33):
        width, _ = board.size()
        if i:
            print('-' * ((width * 2) - 1))
        print_board(board.get())
        board.tick()
        sleep(.5)