Also not using enumerate but no ugly for i range implementation this one from code review uses a generator on live cells only.
http://codereview.stackexchange.com/a/108121/104381 def neighbors(cell): x, y = cell 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 def apply_iteration(board): new_board = set([]) candidates = board.union(set(n for cell in board for n in neighbors(cell))) for cell in candidates: count = sum((n in board) for n in neighbors(cell)) if count == 3 or (count == 2 and cell in board): new_board.add(cell) return new_board if __name__ == "__main__": board = {(0,1), (1,2), (2,0), (2,1), (2,2)} number_of_iterations = 10 for _ in xrange(number_of_iterations): board = apply_iteration(board) print board Sayth -- https://mail.python.org/mailman/listinfo/python-list
