9-1 餐馆 :创建一个名为Restaurant 的类,其方法__init__() 设置两个属性:restaurant_name 和cuisine_type 。创建一个名为describe_restaurant() 的方法和一个名为open_restaurant() 的方法,其中前者打印前述两项信息,而后者打印一条消息,指出餐馆正在营业。
根据这个类创建一个名为restaurant 的实例,分别打印其两个属性,再调用前述两个方法。
代码:
class Restaurant: def __init__(self,restaurant_name, cuisine_type): self.restaurant_name=restaurant_name self.cuisine_type=cuisine_type def describe_restaurant(self): print("Restaurant_name: " + self.restaurant_name.title()) print("Cuisine_type: " + self.cuisine_type.title()) def open_restaurant(self): print("The restaurant is open.") my_restaurant=Restaurant("chinese","chinese style") my_restaurant.describe_restaurant() my_restaurant.open_restaurant()
结果:
Restaurant_name: Chinese Cuisine_type: Chinese Style The restaurant is open.
9-2 三家餐馆 :根据你为完成练习9-1而编写的类创建三个实例,并对每个实例调用方法describe_restaurant() 。
代码:
class Restaurant: def __init__(self,restaurant_name, cuisine_type): self.restaurant_name=restaurant_name self.cuisine_type=cuisine_type def describe_restaurant(self): print("\nRestaurant_name: " + self.restaurant_name.title()) print("Cuisine_type: " + self.cuisine_type.title()) def open_restaurant(self): print("The restaurant is open.") my_restaurant=Restaurant("chinese","chinese style") my_restaurant.describe_restaurant() my_restaurant1=Restaurant("happy time","endlish style") my_restaurant1.describe_restaurant() my_restaurant2=Restaurant("eating","indian style") my_restaurant2.describe_restaurant()
结果:
Restaurant_name: Chinese Cuisine_type: Chinese Style Restaurant_name: Happy Time Cuisine_type: Endlish Style Restaurant_name: Eating Cuisine_type: Indian Style
9-3 用户 :创建一个名为User 的类,其中包含属性first_name 和last_name ,还有用户简介通常会存储的其他几个属性。在类User 中定义一个名为describe_user() 的方法,它打印用户信息摘要;再定义一个名为greet_user() 的方法,它向用户发出个性化的问候。
创建多个表示不同用户的实例,并对每个实例都调用上述两个方法。
代码:
class user: def __init__(self,first_name,last_name): self.first_name=first_name self.last_name=last_name def describe_user(self): print("User'name: "+ self.last_name.title()+" "+ self.first_name.title()) def greet_user(self): print("Hello, " + self.last_name.title()+" "+ self.first_name.title()+"!") user_1=user('geroge',"tim") user_1.describe_user() user_1.greet_user() print("\n") user_2=user('while',"tom") user_2.describe_user() user_2.greet_user() print("\n") user_3=user('li',"ming") user_3.describe_user() user_3.greet_user()
结果:
User'name: Tim Geroge Hello, Tim Geroge! User'name: Tom While Hello, Tom While! User'name: Ming Li Hello, Ming Li!
9-4 就餐人数 :在为完成练习9-1而编写的程序中,添加一个名为number_served 的属性,并将其默认值设置为0。根据这个类创建一个名为restaurant 的实例;打印有多少人在这家餐馆就餐过,然后修改这个值并再次打印它。
添加一个名为set_number_served() 的方法,它让你能够设置就餐人数。调用这个方法并向它传递一个值,然后再次打印这个值。添加一个名为increment_number_served() 的方法,它让你能够将就餐人数递增。调用这个方法并向它传递一个这样的值:你认为这家餐馆每天可能接待的就餐人数。
代码:class Restaurant: def __init__(self,restaurant_name, cuisine_type): self.restaurant_name=restaurant_name self.cuisine_type=cuisine_type self.number_served=0; def describe_restaurant(self): print("Restaurant_name: " + self.restaurant_name.title()) print("Cuisine_type: " + self.cuisine_type.title()) def get_number_served(self): print("The restaurant has served for "+ str(self.number_served) + ".") def open_restaurant(self): print("The restaurant is open.") def set_number_served(self,number): self.number_served=number def increment_number_served(self,increment): self.number_served += increment my_restaurant1=Restaurant("happy time","endlish style") my_restaurant1.describe_restaurant() my_restaurant1.get_number_served() my_restaurant1.set_number_served(98) my_restaurant1.get_number_served() my_restaurant1.increment_number_served(2) my_restaurant1.get_number_served()
结果:
Restaurant_name: Happy Time Cuisine_type: Endlish Style The restaurant has served for 0. The restaurant has served for 98. The restaurant has served for 100.
9-6 冰淇淋小店 :冰淇淋小店是一种特殊的餐馆。编写一个名为IceCreamStand 的类,让它继承你为完成练习9-1或练习9-4而编写的Restaurant 类。这两个版本的Restaurant 类都可以,挑选你更喜欢的那个即可。添加一个名为flavors 的属性,用于存储一个由各种口味的冰淇淋组成的列表。编写一个显示这些冰淇淋的方法。创建一个IceCreamStand 实例,并调用这个方法。
代码:class Restaurant: def __init__(self,restaurant_name, cuisine_type): self.restaurant_name=restaurant_name self.cuisine_type=cuisine_type self.number_served=0; def describe_restaurant(self): print("Restaurant_name: " + self.restaurant_name.title()) print("Cuisine_type: " + self.cuisine_type.title()) def get_number_served(self): print("The restaurant has served for "+ str(self.number_served) + ".") def open_restaurant(self): print("The restaurant is open.") def set_number_served(self,number): self.number_served=number def increment_number_served(self,increment): self.number_served += increment class IceCreamStand(Restaurant): def __init__(self,restaurant_name, cuisine_type) : super().__init__(restaurant_name, cuisine_type) self.flavors = [] def add_flavors(self,kind): self.flavors.append(kind) def get_flavors(self): print(self.flavors) my_IceCreamStand=IceCreamStand("chinese","chinese style") my_IceCreamStand.add_flavors("mango") my_IceCreamStand.add_flavors("apple") my_IceCreamStand.add_flavors("pineapple") my_IceCreamStand.get_flavors()
结果:
['mango', 'apple', 'pineapple']
9-10 导入Restaurant类 :将最新的Restaurant 类存储在一个模块中。在另一个文件中,导入Restaurant 类,创建一个Restaurant 实例,并调用Restaurant 的一个方法,以确认import 语句正确无误。
代码:(restaurant.py)
class Restaurant: def __init__(self,restaurant_name, cuisine_type): self.restaurant_name=restaurant_name self.cuisine_type=cuisine_type self.number_served=0; def describe_restaurant(self): print("Restaurant_name: " + self.restaurant_name.title()) print("Cuisine_type: " + self.cuisine_type.title()) def get_number_served(self): print("The restaurant has served for "+ str(self.number_served) + ".") def open_restaurant(self): print("The restaurant is open.") def set_number_served(self,number): self.number_served=number def increment_number_served(self,increment): self.number_served += increment(my_restaurant.py)
from restaurant import Restaurant my_rerestaurant_1 = Restaurant("chinese","style") my_rerestaurant_1.describe_restaurant()结果:
Restaurant_name: Chinese Cuisine_type: Style
9-14 骰子 :模块random 包含以各种方式生成随机数的函数,其中的randint() 返回一个位于指定范围内的整数,例如,下面的代码返回一个1~6内的整数:
请创建一个Die 类,它包含一个名为sides 的属性,该属性的默认值为6。编写一个名为roll_die() 的方法,它打印位于1和骰子面数之间的随机数。创建一个6面的骰子,再掷10次。 创建一个10面的骰子和一个20面的骰子,并将它们都掷10次。
代码:
from random import randint class Die: def __init__(self): sides=6 def set_sides(self,sides_): self.sides=sides_ def roll_die(self): for a in range(0,10): x = randint(1, self.sides) print(x) My_die = Die() My_die.set_sides(6) My_die.roll_die() print("\n") My_die1 = Die() My_die1.set_sides(10) My_die1.roll_die() print("\n") My_die2 = Die() My_die2.set_sides(20) My_die2.roll_die()
结果:
5 2 2 3 2 2 3 6 5 4 1 4 6 5 3 2 9 9 9 7 14 8 4 14 20 16 1 20 1 5