code: def tiles(self):
          
          images = self.parent.images
          for x, y, gid in [i for i in self.iter_data() if i[2]]:
              yield x, y, images[gid]
docs: Iterate over tile images of this layer
  
          This is an optimised generator function that returns
          (tile_x, tile_y, tile_image) tuples,
  
          :rtype: Generator
          :return: (x, y, image) tuples