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='', memory=''):
        self.brand = brand
        self.color = color
        self.memory = memory

    @staticmethod
    def play_game():
        print('打游戏')

    @staticmethod
    def write_code():
        print('写代码')

    @staticmethod
    def watch_video():
        print('看视频')


def main():
    print('===============作业第一题==================')
    pc = Computer('苹果', '白色', '16G')
    pc.play_game()
    pc.write_code()
    pc.watch_video()

    print('=====通过对象.的方式去操作对象的属性=====')
    # 获取对象的属性
    print(pc.brand, pc.color, pc.memory)

    # 修改对象的属性
    pc.brand = '联想'
    pc.color = '黑色'
    pc.memory = '8G'
    print(pc.brand, pc.color, pc.memory)

    # 添加对象的属性
    pc.name = '小黑'
    print(pc.brand, pc.color, pc.memory, pc.name)

    # 删除对象的属性
    del pc.brand
    # print(pc.brand, pc.color, pc.memory, pc.name)   # AttributeError: 'Computer' object has no attribute 'brand'
    print(pc.color, pc.memory, pc.name)

    print('=====通过attr相关方法操作对象的属性======')
    # 获取对象的属性
    print(getattr(pc, 'color'))
    print(getattr(pc, 'memory'))
    print(getattr(pc, 'name'))

    # 修改对象的属性
    setattr(pc, 'color', '白色')
    setattr(pc, 'memory', '32G')
    setattr(pc, 'name', '小白')

    print(getattr(pc, 'color'))
    print(getattr(pc, 'memory'))
    print(getattr(pc, 'name'))

    # 添加对象的属性
    setattr(pc, 'brand', '小米')

    print(getattr(pc, 'brand'))

    # 删除对象的属性
    delattr(pc, 'name')

    print(getattr(pc, 'name', None))


if __name__ == '__main__':
    main()

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，让他拥有⼀条大黄，然后让小明去遛大黄

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

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


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

    def call_out(self):
        print('%s在叫唤' % self.name)


def main():
    dog = Dog('大黄', '黄色', 5)
    p1 = Person('小明', 18, dog.name)

    p1.walking_the_dog()
    dog.call_out()


if __name__ == '__main__':
    main()

3.声明⼀个圆类:

class Circle:
    def __init__(self, radius=0):
        self.radius = radius

    def circumference(self):
        return 2 * 3.14 * self.radius

    def area_circle(self):
        return 3.14 * self.radius ** 2


def main():
    circle = Circle(5)
    print('圆的周长为%.2f' % circle.circumference())
    print('圆的面积为%.2f' % circle.area_circle())


if __name__ == '__main__':
    main()

4.创建一个学生类:
属性: 姓名，年龄，学号
方法: 答到，展示学生信息

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=0, stu_id=''):
        self.name = name
        self.age = age
        self.stu_id = stu_id

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

    def show_student_info(self):
        print('姓名：%s 年龄：%d 学号：%s' % (self.name, self.age, self.stu_id))


class Clbum:
    def __init__(self, student, class_name=''):
        self.student = student
        self.class_name = class_name

    def add_student(self, stu_dict):
        self.student.append(stu_dict)

    def del_student(self):
        del_list = []
        while True:
            print('1.根据姓名删除学生')
            print('2.根据学号删除学生')
            print('3.退出')
            input_value = input('请选择')
            if input_value == '1':
                del_name = input('请输入要删除的姓名：')
                for stu in self.student:
                    if stu['name'] == del_name:
                        del_list.append(stu)
                index = 0
                for stu in del_list:
                    print(str(index) + ' ' + '姓名：%s 年龄：%s 学号：%s' % (stu['name'], stu['age'], stu['stu_id']))
                    index += 1
                input_value = input('请输入要删除的学生对应的标号：')

                del_stu = del_list[int(input_value)]
                self.student.remove(del_stu)
                print(self.student)
            elif input_value == '2':
                del_id = input('请输入要删除的学号：')
                for stu in self.student:
                    if stu['stu_id'] == del_id:
                        self.student.remove(stu)
                print(self.student)
            elif input_value == '3':
                break
            else:
                print('输入有误。请重新输入！')

    def call_the_roll(self):
        for stu in self.student:
            print('%s' % stu['name'])

    def aver_age(self):
        sum1 = 0
        for stu in self.student:
            sum1 += int(stu['age'])
        return sum1 / len(self.student)


def main():
    stu1 = Student('小明', 18, '1'.rjust(4, '0'))
    stu1.answer()
    stu1.show_student_info()

    grade1 = Clbum([], '一班')
    # 添加学生
    num_people = int(input('请输入学生的人数：'))
    for index in range(1, num_people + 1):
        name = input('请输入学生的姓名：')
        age = input('请输入学生的年龄：')
        stu2 = Student(name, age, str(index).rjust(4, '0'))
        grade1.add_student(stu2.__dict__)
    print(grade1.student)

    # 点到
    grade1.call_the_roll()
    # 计算学生的平均年龄
    aver = grade1.aver_age()
    print('平均年龄为%.2f' % aver)

    # 删除学生
    grade1.del_student()


if __name__ == '__main__':
    main()