设计一个汽车类Vehicle,包含的属性有车轮个数wheels和车重weight。小车类Car是Vehicle的子类,其中包含的属性有载人数loader。卡车类Truck是Car类的子类,其中包含的属性有载重量payload。每个类都有构造方法和输出

下面是一个示例代码：

class Vehicle:
    def __init__(self, wheels, weight):
        self.wheels = wheels
        self.weight = weight

    def output(self):
        print("Vehicle has {} wheels and weighs {} kg.".format(self.wheels, self.weight))

class Car(Vehicle):
    def __init__(self, wheels, weight, loader):
        super().__init__(wheels, weight)
        self.loader = loader

    def output(self):
        print("Car has {} wheels, weighs {} kg, and can carry {} people.".format(self.wheels, self.weight, self.loader))

class Truck(Car):
    def __init__(self, wheels, weight, loader, payload):
        super().__init__(wheels, weight, loader)
        self.payload = payload

    def output(self):
        print("Truck has {} wheels, weighs {} kg, can carry {} people, and can carry {} kg of payload.".format(self.wheels, self.weight, self.loader, self.payload))

这个代码定义了一个 Vehicle 类，一个 Car 类和一个 Truck 类，每个类都有自己的属性和构造方法。每个类都有自己的输出方法 output，用于输出自己的属性。在每个类的构造方法中，使用 super() 调用父类的构造方法来初始化继承的属性。在每个类的 output 方法中，使用格式化字符串来输出自己的属性。