@@ -0,0 +1,617 @@
+class Car:%0A    def __init__(self, top_speed):%0A        self._top_speed = top_speed%0A%0Ap = Car(300)%0Aprint(p._top_speed)%0Ap._top_speed = 20%0Aprint(p._top_speed)%0A%0Aclass Plane:%0A    def __init__(self, top_speed):%0A        self._top_speed = top_speed%0A    @property%0A    def top_speed(self):%0A        return self._top_speed%0A    @top_speed.setter%0A    def top_speed(self, top_speed):%0A        if 0 %3C= top_speed %3C= 3000:%0A            self._top_speed = top_speed%0A        else:%0A            raise ValueError(%22Top speed value range %5B0, 3000%5D%22)%0A%0Apn = Plane(1000)%0Aprint(pn.top_speed)%0Apn.top_speed = 2000%0Aprint(pn.top_speed)%0Apn.top_speed = 6000

Add property demo.