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, color, memsize):
        self.brand = brand
        self.color = color
        self.memsize = memsize

    def info(self):
        print(self.brand, self.color, self.memsize)

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

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

    def watch_tv(self):
        print('看视频')


user1 = Computer('Dell', 'black', '8G')
user2 = Computer('hp', 'white', '16G')

user1.cpu = 'i7'
print(user1.cpu)  # i7

user1.memsize = '16G'
print(user1.memsize)  # 16G

del user2.color
# print(user2.color)  # AttributeError: 'Computer' object has no attribute 'color'

setattr(user1, 'price', 7500)
print(user1.price)  # 7500

setattr(user2, 'memsize', '32G')
print(user2.memsize)  # 32G

# delattr(user2, 'color')
# print(user2.color)  # AttributeError: color

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

    def walk_dog(self):
        print('%s在遛%s' % (people.name, self.dog.name))


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

    def cry(self):
        print('%s:汪汪往' % self.name)


dog1 = Dog('旺财', 'black', '5')
dog2 = Dog('来福', 'black', '5')
dog = dog2
people = Person('小明', '25', dog)
people.walk_dog()

3.声明⼀一个圆类，自己确定有哪些属性和方法

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

    def area(self):
        return self.r**2*3.14

    def perimeter(self):
        return 2*3.14*self.r

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
创建⼀一个班级类:
属性:学⽣生，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:
    def __init__(self, name, age, stu_id):
        self.name = name
        self.age = age
        self.stu_id = stu_id

    def rollcall(self):
        print('%s:到！' % self.name)

    def stu_info(self):
        print('学生信息：', self.name, self.age, self.stu_id)


class Classroom:
    def __init__(self, stu1, classinfo):
        self.stu = stu1
        self.classinfo = classinfo

    def addstu(self):
        stu1.name = ???
        stu1.age = ???
        stu1.stu_id =  ???
        # setattr(stu1, 'name')
        # setattr(stu1, 'age')
        # setattr(stu1, 'stu_id')

    def del_stu(self):
        del stu1.???
        del stu1.???
        del stu1.???

    def age_average(self):
        count = 0
        average = 0
        for i in str(stu1.age):
            count += i
            average = count / int(i)
            print('班级年龄平均值为：%s' % average )

    def rollcall(self):
        print('%s:到!' % self.stu.name)






stu1 = Student('田宇', '24', 'py1904008')
stu2 = Classroom(stu1, 'py1904')