python基础-多重继承

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继承多个父类时,子类中使用哪个父类的属性,跟class语句中这些父类的顺序有关系,以前面的父类的属性为准 ,在python中使用MRO(方法解析顺序)这种算法来查找多重继承下使用哪个父类的属性

class B:
    num = 78

class C:
    num = 70

class A(B, C):
    pass

print(A.__mro__)
print(A().num)

打印结果:

(<class '__main__.A'>, <class '__main__.B'>, <class '__main__.C'>, <class 'object'>)
78

B类在C类前面,所以A继承的num属性是 num = 78

再看一个:

class F:
    pass


class D(F):
    name = 'aa'

class E(F):
    name = 'ww'


class B(D):
    num = 78

class C(E):
    num = 70

class A(B, C):
    pass

print(A.__mro__)
print(A().name)

打印结果:

(<class '__main__.A'>, <class '__main__.B'>, <class '__main__.D'>, <class '__main__.C'>, <class '__main__.E'>, <class '__main__.F'>, <class 'object'>)
aa

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转载自blog.csdn.net/bubblelone/article/details/85918748
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