@property
    def width(self):
        return self._width
    @width.setter
    def width(self,width):
        self._width=width
    @property
    def height(self):
        return self._height
    @height.setter
    def height(self,height):
        self._height=height
    @property
    def resolution(self):
        return (self.width)*(self.height)

先交作业再回炉好好学习，看了2遍还不是很顺溜