学习Python类过程中遇到的问题

class Restaurant:
    def __init__(self, restaurantname, cuisine_type):
        # 设置餐馆的属性...
        self.restaurant_name = restaurantname
        self.cuisine_type = cuisine_type
        self.number_served = 0

    def describe_restaurant(self):
        # 打印餐馆的名字...
        print(f"The restaurant's name is {self.restaurant_name} and it serves {self.cuisine_type} cuisine.")

    def open_restaurant(self):
        # 描述餐馆的状态...
        print("The restaurant is open.")

    def set_number_served(self, new_number):
        # 设置就餐人数...
        self.number_served = new_number

    def describe_restaurant_number(self):
        print(f"There have been {self.number_served} people dining in this restaurant.")

    def increment_number_served(self, increment):
        self.number_served += increment

class IceCreamStand(Restaurant):
    def __init__(self, restaurantname, cuisine_type):
        super().__init__(restaurantname, cuisine_type)
        self.flavors = []

    def flavors_show(self):
        for flavor in self.flavors:
            print(flavor)