1.聲明?個電腦類: 屬性:品牌、顏?、內(nèi)存?小 方法:打游戲、寫代碼、看視頻

a.創(chuàng)建電腦類的對象，然后通過對象點的?方式獲取、修改、添加和刪除它的屬性
b.通過attr相關(guān)?方法去獲取、修改、添加和刪除它的屬性

import random
class Computer:
    """電腦類"""
    def __init__(self, brand, color, ram):
        self.brand = brand
        self.color = color
        self.ram = ram

    def paly_game(self):     # 有波浪號警告，說明選的方法不對
        return '打游戲'

    def write_code(self, lang: str):
        return '寫%s代碼' % lang

    def watch_video(self):
        return '看視頻'

c1 = Computer('華為', '白色', '512G')
print(c1.brand)   # 華為
c1.color = '黑色'
print(c1.color) # 黑色
c1.price = '1000'
print(c1.price)  # 1000
# del c1.price
# print(c1.price)  # AttributeError: 'Computer' object has no attribute 'price'

print(getattr(c1, 'brand'))    # 華為
setattr(c1, 'color', '紅色')
print(c1.color)      # 紅色
setattr(c1, 'price', 200)
print(c1.price)   # 200
# delattr(c1, 'price')
# print(c1.price)  # AttributeError: 'Computer' object has no attribute 'price'

2.聲明?個人的類和狗的類:

狗的屬性:名字、顏?、年齡
狗的?方法:叫喚
人的屬性:名字、年齡、狗
人的?方法:遛狗
a.創(chuàng)建?的對象小明，讓他擁有一條狗大黃，然后讓小明去遛大黃

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

    def shout(self):
       print('%s在叫：汪汪汪' % self.name)


class Person:
    """人類"""
    def __init__(self, name, age):
        self.name = name
        self.age = age      # 擁有年齡
        self.dog = None   # 狗類的對象，具體的某只狗

    def walk_the_dog(self):
        if not self.dog:
            print('沒有狗')
        else:
            print('%s牽著%s在散步' % (self.name, self.dog.name))

p1 = Person('小明', 35)   # 創(chuàng)建人的對象   ？？沒有聲明self.dog就能用？
dog1 = Dog('大黃', '白色', 5)  # 創(chuàng)建狗的對象
p1.dog = dog1 # 讓人擁有狗
p1.walk_the_dog()

3.聲明?圓類，自己確定有哪些屬性和方法

class Circle:
    pi = 3.1415926

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

    def perimeter(self):
        return 2 * Circle.pi * self.radius

    def area(self):
        return Circle.pi * self.radius ** 2
c1 = Circle(3)
print(c1.perimeter())
print(c1.area())

4.創(chuàng)建一個學(xué)?生類:

屬性:姓名，年齡，學(xué)號
方法:答到，展示學(xué)?生信息
創(chuàng)建?個班級類:
屬性:學(xué)生，班級名
方法:添加學(xué)?，刪除學(xué)生，點名, 求班上學(xué)生的平均年齡

class Student:
    def __init__(self, name, age=0, study_id='000'):
        self.name = name
        self.age = age
        self.study_id = study_id
        self.is_in_class = random.randint(0,1)


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

    def show(self):
        print('姓名：%s 年齡：%d 學(xué)號：%s') % (self.name, self.age, self.study_id)


class Class:
    def __init__(self, class_name):
        self.students = [] # 一個班有多個學(xué)生：一個列表，列表中的元素是學(xué)生
        self.class_name = class_name
        def func():
            num = 1
            while True:
                yield 'stu'+str(num)
                num += 1
        self.creat_id = func()  # 學(xué)號生成器


    def add_student(self):
        name = input('學(xué)生姓名；')
        age = int(input('學(xué)生的年齡：'))
        study_id = next(self.creat_id)
        stu = Student(name, age, study_id)
        self.students.append(stu)

    def del_student(self):
        """刪除學(xué)生"""
        del_name = input('請輸入要刪除的學(xué)生的名字：')
        flag = False
        for stu in self.students:
            if stu.name == del_name:
                flag = True
                stu.show()
                input('是否刪除（y/n）')
                if value == 'y':
                    self.students.remove(stu)
        if not flag:
            print('沒有該學(xué)生！')

    def call_name(self):
        """點名"""
        for stu in self.students:
            print(stu.name)
            if stu.is_in_class:
                stu.respond()

    def avg_age(self):
        """求平均年齡"""
        ages = 0
        for stu in self.students():
            ages += stu.age
        return ages / len(self.students)



    def show_all_students(self):
        print('=========%s的學(xué)生============')
        for stu in self.students:
            stu.show()

c1 = Class('py1903')
c2 = Class('py1904')
c1.add_student()    # 001
c1.add_student()    # 002
c2.add_student()    # 001
c1.add_student()    # 003
c1.show_all_students()
c2.show_all_students()