layers.py 文件源码

def __getitem__(self, key):
        """Access a surface by z-index.

        Arguments:
            key (int): The z-index of the surface.

        Raises:
            IndexError: When the z-index is invalid.

        Returns:
            pygame.Surface: The surface belonging
                to the z-index specified.

        """

        return self._surface_layers[key]