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="HP", color="black", ram="10G"):
self.brand = brand
self.color = color
self.ram = ram
def play_game(self):
print("we use %s to play computer game" % self.brand)
def coding(self):
print("we use %s to code" % self.brand)
def watch_video(self):
print("we use %s to watch the video" % self.brand)
computer = Computer("hp", "red", "2g")
# 通过点方法获取类的属性
print(computer.brand, computer.color, computer.ram) # hp red 2g
# 通过点方法修改类的属性
computer.ram = "4g"
print(computer.ram) # 4g
# 通过点方法添加类的属性
computer.size = "17"
print(computer.size) # 17
# 通过点方法删除类的属性
del computer.color
# print(computer.color) # AttributeError: 'Computer' object has no attribute 'color'
# 通过getattr方法获取属性
print(getattr(computer, "brand")) # hp
# 通过方法修改类的属性
setattr(computer, "size", 21)
print(getattr(computer, "size")) # 21
# 通过方法添加类的属性
setattr(computer, "screen", "retina")
print(getattr(computer, "screen")) # retina
# 通过方法删除类的属性
delattr(computer, "screen")
# print(computer.screen) # AttributeError: 'Computer' object has no attribute 'screen'
# 打游戏
print(computer.play_game()) # we use hp to play computer game
print(computer.coding()) # we use hp to code
print(computer.watch_video()) # we use hp to watch the video
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，让他拥有一条狗大黄，然后让小明去遛大黄
class Dog:
def __init__(self, name, color, age):
self.name = name
self.color = color
self.age = age
def bark(self):
print("%s 会叫”汪汪汪~~~“" % self.name)
class Human():
def __init__(self, name, age, pets):
self.name = name
self.age = age
self.pets = pets
def walk_the_dog(self):
print("%s遛%s" % (self.name, self.pets))
dog=Dog("大黄","yellow",3)
ming=Human("小明",14,dog.name)
print(ming.walk_the_dog())
# 小明遛大黄
import math
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 math.pi * self.r ** 2
def perimeter(self):
return 2 * self.r * math.pi
def boll(self):
return math.pi * self.r ** 3
circle = Circle(3)
print(float(circle.perimeter()))
print(circle.area())
print(circle.boll())
# 18.84955592153876
# 28.274333882308138
# 84.82300164692441
