day15-作业

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="黑色", flash="8G"):
        self.brand = brand
        self.color = color
        self.flash = flash

    def play_game(self):
        print("打游戏中~")

    def coding(self):
        print("写代码中~")

    def watch_video(self):
        print("看视频中～")


# 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
# 查
computer = Computer("联想")
print(computer.color)
# 改
computer.flash = "18G"
print(computer.flash)
# 增
computer.cpu = "i5"
print(computer.cpu)
# 删
del computer.cpu

# b.通过attr相关⽅方法去获取、修改、添加和删除它的属性
# 查
print(getattr(computer, "color"))
# 改
setattr(computer, "flash", "8G")
print(computer.flash)
# 增
setattr(computer,"cpu","i7")
print(computer.cpu)
# 删
delattr(computer,"cpu")
print(getattr(computer,"cpu",None))

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，让他拥有⼀条狗大⻩，然后让⼩明去遛大黄

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

    def call(self):
        print(self.name + "在叫唤")


class Person:
    def __init__(self, name: str, age: int, dog: Dog):
        self.name = name
        self.age = age
        self.dog = dog

    def walk_the_dog(self):
        print(self.name, "正在遛他的", self.dog.name)
        self.dog.call()

dh = Dog("大黄", "黄色", 2)

xm = Person("小明", 12, dh)
xm.walk_the_dog()

3. 声明一个圆类:

class Circle:
    PI = 3.1415926

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

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

    def perimeter(self):
        return 2 * self.PI * self.radius
c = Circle(3)
print(c.area())
print(c.perimeter())

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: str, age: int, id: str):
        self.name = name
        self.age = age
        self.id = id

    def __repr__(self):
        return ("学号：%s 姓名：%s 年龄：%d" % (self.id, self.name, self.age))


class Class:
    def __init__(self, class_name: str):
        self.all_student = []
        self.class_name = class_name

    def add_student(self, student: Student):
        self.all_student.append(student)

    def del_student(self, student):
        for s in self.all_student[:]:
            if s == student:
                self.all_student.remove(s)

    def average(self):
        age_sum = sum(x.age for x in self.all_student)
        return age_sum / len(self.all_student)

    def __repr__(self):
        s = ""
        for student in self.all_student:
            s += str(student) + "\n"
        return s


classa = Class("三年级二班")

classa.add_student(Student("小明", 10, "001"))
classa.add_student(Student("小东", 12, "002"))
classa.add_student(Student("小强", 13, "003"))
classa.add_student(Student("小红", 14, "004"))

print(classa.average())

print(classa)