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:
    __slots__ = ('brand', 'color', 'memory', 'price', 'cpu')

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

    def play_game(self):
        print('打游戏')

    def write_code(self):
        print('敲代码')

    def watch(self):
        print('看电视')


computer1 = Computer('dell', 'red', '16G')

computer2 = Computer('hp', 'black', '8G')
print(computer1.brand, computer1.color, computer1.memory)
print(computer2.brand, computer2.color, computer2.memory)

computer1.play_game()
computer2.write_code()
computer2.watch()

computer1.cpu = 'inter'
print(computer1.cpu)
setattr(computer1, 'price', 'rmb:8080')
print(computer1.price)

delattr(computer2, 'brand')
del computer2.color
print(computer2.brand, computer2.color, computer2.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 Person:
    __slots__ = ('name', 'age', 'dog')

    def __init__(self, name, age, dog):
        self.name = name
        self.age = age
        self.dog = dog

    def hang_dog(self):
        print('%s牵着%s去公园玩儿' % (self.name, self.dog))


class Dog:
    __slots__ = ('dog_name', 'dog_color', 'dog_age')

    def __init__(self, dog_name, dog_color, dog_age):
        self.dog_name = dog_name
        self.dog_color = dog_color
        self.dog_age = dog_age

    def bark(self):
        print('%s在公园汪汪叫' % self.dog_name)


p1 = Person('小明', 16, '大黄')
dog1 = Dog(p1.dog, 'white', '2')
print(p1.name, p1.age, p1.dog)
print(dog1.dog_name, dog1.dog_color, dog1.dog_age)
p1.hang_dog()
dog1.bark()

3.声明⼀一个圆类，自己确定有哪些属性和方法

from math import pi


class Circle:
    __slots__ = ('r', 'color')

    def __init__(self, r, color):
        self.r = r
        self.color = color

    def premiter(self):
        print(2*pi*self.r)

    def area(self):
        print(pi*self.r*self.r)


circle1 = Circle(5, 'red')
circle1.area()
circle1.premiter()

4.创建⼀一个学⽣生类:
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:添加学⽣生，删除学生，点名, 求班上学生的平均年龄

class Student:
    __slots__ = ('name', 'age', 'stu_id', 'class_id')

    def __init__(self, name, age, stu_id):
        self.name = name
        self.age = age
        self.stu_id = stu_id

    def reply(self):
        print('%s已就位' % self.name)


stu1 = Student('王力', '18', '1904')
stu1.reply()


class Class:
    __slots__ = ('name', 'class_id', 'age', 'stu_id')

    def __init__(self, name, class_id, age, stu_id):
        self.name = name
        self.class_id = class_id
        self.age = age
        self.stu_id = stu_id

    def add_stu(self):
        self.name = input('学生姓名：')
        self.age = input('学生年龄：')
        self.stu_id = input('学生学号：')
        self.class_id = input('学生班级：')

    def del_stu(self):
        self.name = input('要删除的学生姓名：')
        del (self.name, self.age, self.stu_id, self.class_id)
        print('删除成功')


class1 = Class(None, None, None, None)
class1.add_stu()
print(class1.name, class1.age, class1.stu_id, class1.class_id)


class1.del_stu()
print(class1.name, class1.age, class1.stu_id, class1.class_id)