@property def width(self): return self._width

@width.setter def width(self,width): if not isinstance(width,int): raise TypeError('Expected int') self._width = width

@property def height(self): return self._height

@height.setter def height(self,height): if not isinstance(height,int): raise TypeError('Expected int') self._height = height

@property def resolution(self): return self.width * self.height

这里的self.width和self._width有什么区别吗？