Task10:类、对象与魔法方法

思维导图

代码

#对象是类的实例，对象=属性+方法
class Turtle:#类要以大写字母开头
    #以下为属性
    color='green'
    weight=10
    legs=4
    shell=True
    mouth='大嘴'

    def climb(self):
        print('我正在努力的向前爬')

    def run(self):
        print('我正在飞快地向前跑')

tt=Turtle()
print(tt)

tt.climb()

#继承：子类自动共享父类之间的数据和方法的机制
class MyList(list):
    pass

lst=MyList([1,5,2,7,8])
lst.append(9)
lst.sort()
print(lst)


#多态：不同对象对同一方法响应不同的行动
class Animal:
    def run(self):
        raise AttributeError('子类必须实现这个方法')

class People(Animal):
    def run(self):
        print('人正在走')

class Pig(Animal):
    def run(self):
        print('pig is walking')

def func(animal):
    animal.run()

func(Pig())



class Ball:
    def __init__(self,name):
        self.name=name
    def kick(self):
        print('我叫%s,该死的，谁踢我'%self.name)

a=Ball('球A')
b=Ball('球B')
c=Ball('球C')
a.kick()
b.kick()


class JustCounter:
    __secretCount=0#私有变量
    publicCount=0#公有变量
    def count(self):
        self.__secretCount+=1
        self.publicCount+=1
        print(self.__secretCount)

counter=JustCounter()
counter.count()
counter.count()
print(counter.__JustCounter__secertCount)


#类的私有方法实例
class Site:
    def __init__(self,name,url):
        self.name=name
        self._url=url

    def who(self):
        print('name:',self.name)
        print('url:',self._url)

    def __foo(self):
        print('这是私有方法')

    def foo(self):
        print('这是公共方法')
        self.__foo()

x=Site('熊熊和兔兔的冰激凌世界','Http://123.com')
x.who()
x.foo()

#继承
class people:
    name=''
    age=0
    __weight=0#定义私有属性，外部无法直接进行访问

    def __init__(self,n,a,w):
        self.name=n
        self.age=a
        self.__weight=w

    def speak(self):
        print('%s说：我%d岁。'%(self.name,self.age))

class student(people):
    grade=''

    def __init__(self,n,a,w,g):#调用父类的构函
        people.__init__(self,n,a,w)
        self.grade=g
        #覆盖父类的方法
    def speak(self):
        print('%s 说：我%d岁了，我在读%d年级'%(self.name,self.age,self.grade))

s=student('小熊',10,60,3)
s.speak()

#组合
class Turtle:
    def __init__(self,x):
        self.num=x

class Fish:
    def __init__(self,x):
        self.num=x

class Pool:
    def __init__(self,x,y):
        self.turtle=Turtle(x)
        self.fish=Fish(y)

    def print_num(self):
        print('水池里有乌龟%s只，小鱼%s条'%(self.turtle.num,self.fish.num))

p=Pool(2,3)
p.print_num()

# 创建类对象
class Test(object):
    class_attr = 100

    def __init__(self):
        self.sl_attr = 100

    def func(self):
        print('类对象.类属性的值：', Test.class_attr)
        print('self.类属性的值', self.class_attr)
        print('self.实例属性的值', self.sl_attr)

a=Test()
a.func()

b=Test()
b.func()

a.class_attr=200
a.sl_attr=200
a.func()
b.func()

Test.class_attr=300
a.func()
b.func( )
#绑定
class CC:
    def setXY(self,x,y):
        self.x=x
        self.y=y
    def printXY(self):
        print(self.x,self.y)

dd=CC()
print(dd.__dict__)
print(vars(dd))

print(CC.__dict__)
#直接用CC.结果会很奇怪
dd.setXY(4,5)
print(dd.__dict__)

#hasattr()用于判断对象是否包含对应的属性
class Coordinate:
    x = 10
    y = -5
    z = 0
point1 = Coordinate()
print(hasattr(point1, 'x'))
print(hasattr(point1, 'y'))
print(hasattr(point1, 'z'))
print(hasattr(point1, 'no'))


#getattr是用于返回一个对象的属性值
class A(object):
    bar = 1

a = A()
print(getattr(a, 'bar')) # 1
print(getattr(a, 'bar2', 3)) # 3是默认值



class A(object):
    def set(self,a,b):
        x=a
        a=b
        b=x
        print(a,b)

a=A()
c=getattr(a,'set')
c(a='1',b='2')

class A(object):
    bar=1

a=A()
print(getattr(a,'bar'))
setattr(a,'bar',5)
print(a.bar)
setattr(a,'age',28)
print(a.age)