python中的链调用父初始化程序 [英] Chain-calling parent initialisers in python

问题描述

考虑一下-基类A，从A继承的类B，从B继承的类C.在初始化器中调用父类初始化器的通用方法是什么?如果这听起来仍然不太明确，请使用以下代码.

Consider this - a base class A, class B inheriting from A, class C inheriting from B. What is a generic way to call a parent class initialiser in an initialiser? If this still sounds too vague, here's some code.

class A(object):
    def __init__(self):
        print "Initialiser A was called"

class B(A):
    def __init__(self):
        super(B,self).__init__()
        print "Initialiser B was called"

class C(B):
    def __init__(self):
        super(C,self).__init__()
        print "Initialiser C was called"

c = C()

这就是我现在的做法.但这似乎还是太普通了-您仍然必须手动传递正确的类型.

This is how I do it now. But it still seems a bit too non-generic - you still must pass a correct type by hand.

现在，我尝试使用self.__class__作为super()的第一个参数，但是，显然，它不起作用-如果将其放在C的初始化程序中-足够公平，B的初始化程序将被调用.如果在B中执行相同的操作，则"self"仍指向C的一个实例，因此您最终再次调用B的初始化程序(此操作以无限递归结束).

Now, I've tried using self.__class__ as a first argument to super(), but, obviously it doesn't work - if you put it in the initialiser for C - fair enough, B's initialiser gets called. If you do the same in B, "self" still points to an instance of C so you end up calling B's initialiser again (this ends in an infinite recursion).

目前无需考虑钻石继承，我只是想解决这个特定问题.

There is no need to think about diamond inheritance for now, I am just interested in solving this specific problem.

推荐答案

推荐的方法确实是推荐的方法(对于Python 2.x).

The way you are doing it is indeed the recommended one (for Python 2.x).

是否将类显式传递给super的问题是样式问题，而不是功能问题.将类传递给super符合Python的显式优于隐式"的哲学.

The issue of whether the class is passed explicitly to super is a matter of style rather than functionality. Passing the class to super fits in with Python's philosophy of "explicit is better than implicit".

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