Python继承和__init__ [英] Python Inheritance and __init__

问题描述

我正在学习Python，并且发现了一些有关Python如何构造使我感到困惑的子类的信息.

I'm learning Python and I've found something about how Python constructs a sub class which confuses me.

我有一个从列表类继承的类，如下所示.

I have a class that inherits from the list class as follows.

class foo(list):
    def __init__(self, a_bar):
        list.__init__([])
        self.bar = a_bar

我知道list.__init__([])必须在那儿，但对此我感到困惑.在我看来，这行代码只会创建一个新的列表对象，然后将其分配为空，因此我怀疑它只会收集垃圾. Python如何知道此列表是我对象的一部分?我怀疑幕后有事发生，我想知道那是什么.

I know that list.__init__([]) needs to be there but I'm confused about it. It seems to me that this line will just create a new list object and then assign it to nothing, so I would suspect that it would just get garbage collected. How does Python know that this list is part of my object? I suspect that there is something happening behind the scenes and I'd like to know what it is.

推荐答案

实现多重继承安全的方法是:

The multiple-inheritance-safe way of doing it is:

class foo(list):
    def __init__(self, a_bar):
        super(foo, self).__init__()
        ...

这也许可以使您更清楚地知道您在调用基类ctor.

which, perhaps, makes it clearer that you're calling the baseclass ctor.

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