1.声明⼀个电脑类: 属性:品牌、颜⾊、内存⼤小 方法:打游戏、写代码、看视频

a.创建电脑类的对象，然后通过对象点的⽅方式获取、修改、添加和删除它的属性

b.通过attr相关⽅方法去获取、修改、添加和删除它的属性

class Computer:
    def __init__(self,brand:str,color:str,memory=0):
        self.brand=brand
        self.color=color
        self.memory=memory
    def play_games(self):
        print("The feture of playing game")
    def coding(self):
        print("The feture of coding")
    def video(self):
        print("The feture of watching video")

com1=Computer("apple","white",memory=4096)
print(com1.__dict__)
print(com1.brand)#查
com1.memory=2048#改
print(com1.memory)
com1.price=124455#增
print(com1.price)
del com1.color#删除
print(com1.__dict__)
com2=Computer("Thinkpad","black",memory=1565)
print(com2.__dict__)
print(getattr(com2,"brand","None"))#查
setattr(com2,"memory",4096)#改
print(getattr(com2,"memory","None"))
setattr(com2,"price",17554)#增
print(getattr(com2,"price","None"))
delattr(com2,"color")#删除
print(com2.__dict__)

{'brand': 'apple', 'color': 'white', 'memory': 4096}
apple
2048
124455
{'brand': 'apple', 'memory': 2048, 'price': 124455}
{'brand': 'Thinkpad', 'color': 'black', 'memory': 1565}
Thinkpad
4096
17554
{'brand': 'Thinkpad', 'memory': 4096, 'price': 17554}

2.声明⼀个人的类和狗的类:

狗的属性:名字、颜⾊色、年年龄

狗的⽅方法:叫唤

人的属性:名字、年年龄、狗

人的⽅方法:遛狗

a.创建⼈人的对象⼩小明，让他拥有⼀一条狗⼤大⻩黄，然后让⼩小明去遛⼤大⻩黄

class Dog:
    def __init__(self,name:str,color:str,age=0):
        self.name=name
        self.color=color
        self.age=age
    def bellowing(self):
        print("wang...wang...wang..")
class Person:
    def __init__(self,name:str,dog:str,age=0,):
        self.name=name
        self.age=age
        self.dog=dog
    def take_the_dog(self):
        print("%s遛%s"%(self.name,self.dog))
dog1=Dog("大黄","yellow",age=6)
print(dog1.__dict__)
dog1.bellowing()
boy=Person("小明","大黄",age=18)
print(boy.__dict__)
boy.take_the_dog()

{'name': '大黄', 'color': 'yellow', 'age': 6}
wang...wang...wang..
{'name': '小明', 'age': 18, 'dog': '大黄'}
小明遛大黄

3.声明⼀一个圆类，自己确定有哪些属性和方法

import math
class Circle:
    def __init__(self,radius):
        self.radius=radius
    def perimeter(self):
        return 2*(self.radius)*math.pi
    def area(self):
        return(self.radius)**2 *math.pi
cir1=Circle(3)
print("area:%.2f"%cir1.area())
print("perimeter:%.2f"%cir1.perimeter())

area:28.27
perimeter:18.85