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

    def games(self, game):
        return "可以打" + game

    def codes(self, code):
        return "可以敲" + code

    def video(self, video):
        return "可以看" + video


com1 = Computer('联想', '白色', '4G')
print(com1.games('英雄联盟'))
print(com1.codes('python'))
print(com1.video('葫芦娃'))

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

print(com1.brand)
com1.brand = '戴尔'
print(com1.brand)
com1.ram = '400G'
print(com1.ram)
del com1.ram
# print(com1.ram)         #AttributeError: 'Computer' object has no attribute 'ram'

b.通过attr相关⽅方法去获取、修改、添加和删除它的属性

print(getattr(com1, 'brand'))
setattr(com1, 'brand', '联想')
print(getattr(com1, 'brand'))
setattr(com1, 'ram', '400G')
print(getattr(com1, 'ram'))
delattr(com1, 'ram')
# print(getattr(com1, 'ram'))             #AttributeError: 'Computer' object has no attribute 'ram'

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、年年龄、狗
• 人的方法:遛狗

class Dogs:
    def __init__(self, name, color, age=0):
        self.name = name
        self.color = color
        self.age = age


    @classmethod
    def bark(cls):
        return '狗叫'


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

    def walk_dog(self):
        return self.name+ '遛' + self.dog.name

• a.创建⼈人的对象⼩小明，让他拥有⼀一条狗大黄，然后让小明去遛大⻩

dahuang = Dogs('大黄', '黄色')
xiaoming = Human('小明', 18, dahuang)
print(xiaoming.walk_dog())

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 Round:
    def __init__(self, radius:float):
        self.radius = radius

    def area(self):
        return '面积：%.2f'% pi*(self.radius**2)

    def perimeter(self):
        return '周长：%.2f'% (pi*2*self.radius)


print(Round(1).area())
print(Round(1).perimeter())

4.创建⼀一个学⽣生类:

• 属性:姓名，年龄，学号
• 方法:答到，展示学生信息

class Students:
    def __init__(self, name:str, number:str, age:int):
        self.name = name
        self.number = number
        self.age = age

    def inf(self):
        print('姓名:%s 学号：%s' %(self.name, self.number))

    def reply(self):
        print('%s 到'%self.number)

创建⼀一个班级类:

• 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 Class:
    def __init__(self, class_name: str, students=[]):
        self.students = students
        self.class_name = class_name

    def add_stu(self, student):
        self.students.append(student)

    def del_stu(self,student):
        self.students.remove(student)

    @classmethod
    def call_num(cls, number):
        print(number)

    def avg_age(self):
        age = 0
        for student in self.students:
            age +=student.age
        avg_age = age / len(self.students)
        return avg_age



stu1 = Students('小李', '1', 18)
stu2 = Students('小张', '2', 19)
stu3 = Students('小赵', '3', 20)
stu4 = Students('小刘', '4', 21)

cls1 = Class('python1901')

#添加学生
cls1.add_stu(stu1)
cls1.add_stu(stu2)
cls1.add_stu(stu3)
cls1.add_stu(stu4)

print(cls1.students)

for student in cls1.students:
    print(student.name)
#删除学生
# cls1.del_stu(stu1)
#
# print(cls1.students[0].name)

#点到
Class.call_num(1)
stu1.reply()

#求班上学生的平均年龄
print(cls1.avg_age())

#展示学生信息
print(stu1.inf())