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

class Computer:
    def __init__(self, brand, color, memory, ):
        self.brand = brand
        self.color = color
        self.memory = memory

    def game(self):
        return '用%s的电脑打游戏' % self.brand

    def code(self):
        return '用%s的电脑写代码' % self.brand

    def video(self):
        return '用%s的电脑看视频' % self.brand

a.创建电脑类的对象，然后通过对象点的方式获取、修改、添加和删除它的属性

com1 = Computer('联想', '红色', '8GB')
print(com1.color)
com1.color = '黑色'
print(com1.color)
com1.cpu = 'i5'
print(com1.cpu)
del com1.brand

b.通过attr相关方法去获取、修改、添加和删除它的属性

com2 = Computer('苹果', '灰色', '4GB')
print(getattr(com2, 'color'))
setattr(com2, 'color', '白色')
print(getattr(com2, 'color'))
setattr(com2, 'cpu', 'os')
print(getattr(com2, 'cpu'))
delattr(com2, 'memory')

2.声明一个人的类和狗的类:
狗的属性:名字、颜色、年龄
狗的方法:叫唤
人的属性:名字、年龄、狗
人的方法:遛狗
a.创建人的对象小明，让他拥有一条狗大黄，然后让小明去遛大黄

class Dog:
    def __init__(self, name1, color, age1):
        self.name = name1
        self.color = color
        self.age = age1

    @staticmethod
    def bark():
        print('叫唤')


class Person:
    def __init__(self, name2, age2, dog):
        self.name = name2
        self.age = age2
        self.dog = dog

    def walkTheDog(self):
        print('%s遛%s' % (self.name, self.dog))


dog1 = Dog('大黄', '黄色', 3)
person1 = Person('小明', 23, dog1.name)
person1.walkTheDog()

3.声明一个圆类，自己确定有哪些属性和方法

import math

n = math.pi


class Circle:
    def __init__(self, radius):
        self.radius = radius

    def perimeter(self):
        return 2 * n * self.radius

    def area(self):
        return n * (self.radius ** 2)

4.创建一个学生类:
属性:姓名，年龄，学号
方法:答到，展示学⽣生信息
创建一个班级类:
属性:学生，班级名
方法:添加学生，删除学生，点名, 求班上学生的平均年龄

class Student:
    def __init__(self, name, age, num):
        self.name = name
        self.age = age
        self.num = num

    def class_name(self):
        print('到,我叫%s,年龄%d岁,学号%d'%(self.name,self.age,self.num))
    def dict1(self):
        dict1 = {'姓名':self.name,'年龄':self.age,'学号':self.num}
        return dict1
stu1 = Student('小明',17,23)
stu1.class_name()
stu2 = Student('小红',18,24)
stu3 = Student('小聪',20,45)

class Class:
    def __init__(self,list1=[],class_name='一班'):
        self.student = list1
        self.class_name = class_name

    def add_stu(self,student):
        """添加学生"""
        self.student.append(student)
        print(self.student)
    def delete(self,student):
        self.student.remove(student)
        print(self.student)
    def call_name(self):
        for item in self.student:
            print(item['姓名'])
    def v_age(self):
        count = 0
        sum = 0
        for item in self.student:
            sum += item['年龄']
            count+=1
        print(sum/count)

c1 = Class([stu1.dict1()])
c1.add_stu(stu2.dict1())
c1.add_stu(stu3.dict1())
c1.v_age()