python多继承

BitTigerio 2018-02-03

# class People:  #经典类
 class People(object):  #新式类
     def __init__(self,name,age):
         self.name=name
         self.age=age
         self.friends=[]
     def eat(self):
         print("%s is eating." % self.name)
     def sleep(self):
         print("%s is sleeping." % self.name)
 class Relation(object):
     def make_friends(self,obj):
         print('%s is making friends with %s' %(self.name,obj.name))
         self.friends.append(obj)
         obj.friends.append(self)
 
 class Man(People,Relation):    #多继承,继承顺序从左到右
     def __init__(self,name,age,money):
         # People.__init__(self,name,age)
         super(Man, self).__init__(name,age)    #新式类写法
         self.property=money
         print('%s has %s yuan when he was born'%(self.name,self.property))
     def sleep(self):    #重构
         #People.sleep(self)    #继承父类
         super(Man,self).sleep()
         print('%s is dahaning' %  self.name)
 class Woman(Relation,People<span>): <br /><br /> #多继承(构造函数只需要一个),继承顺序从左到右,\ <br /> #第一个父类有构造函数,就不会执行第二个父类的构造函数;如果第一个父类没有构造函数,就去第二个父类中找 <br /><br /> pass <br /><br />
m1=Man('alex',33,10)
 w1=Woman('May',35)
 
 m1.make_friends(w1)
 print(m1.friends[0].name)
 print(w1.friends[0].name)

Man和Woman类都继承了People和Relation两个父类,但Relation类中没有构造函数。Woman实例化时,会先去Relation类中去找构造函数,因为没找到,所以去People类中再找构造函数(从左往右的顺序)。

关于继承顺序:

在python2中新式类是按广度优先继承的,经典类是按深度优先继承的<br />在python3中新式类和经典类都是按广度优先继承的

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Kwong / 0评论 2019-06-11