Binary matrices

binmatrix.py

from collections import MutableMapping


class BinMatrix(MutableMapping):
    def __init__(self, width, height):
        self.width = width
        self.height = height
        self.ALIVE = 1
        self.DEAD = 0
        self._set = set()
    
    def __getitem__(self, (x, y)):
        return self.ALIVE if (x, y) in self._set else self.DEAD
    
    def __setitem__(self, (x, y), value):
        if value:
            self._set.add((x, y))
        else:
            self._set.discard((x, y))
    
    def __delitem__(self, (x, y)):
        self._set.discard((x, y))
    
    def __len__(self):
        return self.width * self.height
    
    def __iter__(self):
        for x in self.columns():
            for y in self.rows():
                yield (x, y)
    
    def rows(self):
        return xrange(self.height)
    
    def columns(self):
        return xrange(self.width)
    
    def rows_items(self):
        for y in self.rows():
            yield (y, (self[(x, y)] for x in self.columns()))
    
    def rows_values(self):
        for _, v in self.rows_items():
            yield v
    
    def columns_items(self):
        for x in self.columns():
            yield (x, (self[(x, y)] for y in self.columns()))
    
    def columns_values(self):
        for _, v in self.columns_items():
            yield v
    
    def neighbors(self, (x, y)):
        pass # TODO
    
    def neighbors_items(self, (x, y)):
        for u, v in self.neighbors((x, y)):
            yield self[(u, v)]
    
    def neighbors_values(self, (x, y)):
        for _, v in self.neighbors_items((x, y)):
            yield v
    
    def display(self, char_alive='X', char_dead='.'):
        d = {self.ALIVE: char_alive, self.DEAD: char_dead}
        
        return '\n'.join(
            ''.join(d[cell] for cell in row) for row in self.rows_values()
        )
    
    def __str__(self):
        return self.display()