Python:在同一实例上多次调用__init __() [英] Python: multiple calls to __init__() on the same instance

问题描述

__init__()函数在创建对象时被调用. 创建对象后，是否可以再次调用对象__init__()函数?

The __init__() function gets called when object is created. Is it ok to call an object __init__() function again, after its been created?

instance = cls(p1=1, p2=2)
# some code
instance.__init__(p1=123, p2=234)
# some more code
instance.__init__(p1=23, p2=24)

为什么有人要在已创建的对象上调用__init__()?

why would anyone wanna call __init__() on an object that is already created?

好问题.我想重新初始化实例的字段.

good question. i wanna re-initialize the instance's fields.

推荐答案

在对象上多次调用__init__很好，只要对__init__进行了编码即可获得想要的效果(无论如何是).发生这种情况的一种典型情况(因此，最好为__init__编写适当的代码！-)是当类的__new__方法返回该类的实例时:确实会导致__init__被

It's fine to call __init__ more than once on an object, as long as __init__ is coded with the effect you want to obtain (whatever that may be). A typical case where it happens (so you'd better code __init__ appropriately!-) is when your class's __new__ method returns an instance of the class: that does cause __init__ to be called on the returned instance (for what might be the second, or twentieth, time, if you keep "recycling" instances via your __new__!-).

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