python第八次練習

例題9-1 餐館

   描述：創建Restaurant 類，
              init() 設置兩個屬性：restaurant_name 和cuisine_type 。
              創建一個名爲describe_restaurant() 的方法
              和一個名爲open_restaurant() 的方法，
              其中前者打印前述兩項信息，而後者打印一條消息，
              指出餐館正在營業。
   代碼：

class Restaurant():
    def __init__(self, restaurant_name, cuisine_type):
        self.name = restaurant_name
        self.type = cuisine_type
    def describe_restaurant(self):
        print('Restaurant name: ' + self.name)
        print('Cuisine type: ' + self.type)
    def open_restaurant(self):
        print(self.name + ' is opening.')
restaurant = Restaurant('MCdownald', 'fast food')
print(restaurant.name)
print(restaurant.type)
restaurant.describe_restaurant()
restaurant.open_restaurant()

   結果：

例題9-4

   描述：在爲完成練習9-1而編寫的程序中，
              添加一個名爲number_served 的屬性，
              並將其默認值設置爲0。
              根據這個類創建一個名爲restaurant 的實例；
              打印有多少人在這家餐館就餐過，
              然後修改這個值並再次打印它。
              添加一個名爲set_number_served() 的方法，
              它讓你能夠設置就餐人數。
              調用這個方法並向它傳遞一個值，
              然後再次打印這個值。
              添加一個名爲increment_number_served() 的方法，
              它讓你能夠將就餐人數遞增。
              調用這個方法並向它傳遞一個這樣的值：
              你認爲這家餐館每天可能接待的就餐人數。
   代碼：

class Restaurant():
    def __init__(self, restaurant_name, cuisine_type):
        self.restaurant_name = restaurant_name
        self.cuisine_type = cuisine_type
        self.number_served = 0
    def set_number_served(self, people):
        self.number_served = people
    def increment_number_served(self, increment):
        self.number_served += increment
    def read_number_served(self):
        print('The restaurant has served ' + str(self.number_served) + ' people.')
    def describe_restaurant(self):
        print('Restaurant name: ' + self.restaurant_name)
        print('Cuisine type: ' + self.cuisine_type)
    def open_restaurant(self):
        print(self.restaurant_name + ' is opening.')
restaurant = Restaurant('MCdownald', 'fast food')
print(restaurant.restaurant_name)
print(restaurant.cuisine_type)
restaurant.describe_restaurant()
restaurant.open_restaurant()
restaurant.read_number_served()
restaurant.set_number_served(10)
restaurant.read_number_served()
restaurant.increment_number_served(10)
restaurant.read_number_served()

   結果：

例題9-6

   描述：冰淇淋小店是一種特殊的餐館。
              編寫一個名爲IceCreamStand 的類，
              讓它繼承你爲完成練習9-1或練習9-4而編寫的Restaurant 類。
              這兩個版本的Restaurant 類都可以，
              挑選你更喜歡的那個即可。
              添加一個名爲flavors 的屬性，
              用於存儲一個由各種口味的冰淇淋組成的列表。
              編寫一個顯示這些冰淇淋的方法。
              創建一個IceCreamStand 實例，並調用這個方法。
   代碼：

class Restaurant():
    def __init__(self, restaurant_name, cuisine_type):
        self.restaurant_name = restaurant_name
        self.cuisine_type = cuisine_type
        self.number_served = 0

    def set_number_served(self, people):
        self.number_served = people

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

    def read_number_served(self):
        print('The restaurant has served ' + str(self.number_served) + ' people.')

    def describe_restaurant(self):
        print('Restaurant name: ' + self.restaurant_name)
        print('Cuisine type: ' + self.cuisine_type)

    def open_restaurant(self):
        print(self.restaurant_name + ' is opening.')

class IceCreamStand(Restaurant):
    def __init__(self, restaurant_name, cuisine_type, flavors):
        super().__init__(restaurant_name, cuisine_type)
        self.flavors = flavors
    def read_flavors(self):
        print('We have the following flavors: ')
        for flavor in self.flavors:
            print(flavor)

flavors = ['Vanilla', 'Mango', 'Strawberry']
ice_restaurant = IceCreamStand('Haagen-Dazs', 'ice cream restaurant', flavors[:])
print(ice_restaurant.restaurant_name)
print(ice_restaurant.cuisine_type)
ice_restaurant.describe_restaurant()
ice_restaurant.open_restaurant()
ice_restaurant.read_number_served()
ice_restaurant.set_number_served(10)
ice_restaurant.read_number_served()
ice_restaurant.increment_number_served(10)
ice_restaurant.read_number_served()
ice_restaurant.read_flavors()

   結果：

發現的問題：

1. init()名稱固定 兩邊是兩個下劃線
2. Def
3. 必須要有self這個參數
4. 實例：restaurant = Restaurant()
5. 可以在類外改變類的變量
6. Super（）不用傳self