克服 Python 关于实例方法的限制

2022-01-20 00:00:00 python 复制 oop instance-method

问题描述

似乎 Python 在实例方法方面有一些限制.

It seems that Python has some limitations regarding instance methods.

  1. 无法复制实例方法.
  2. 实例方法不能被pickle.

这对我来说是个问题，因为我在一个非常面向对象的项目中工作，我在其中引用了实例方法，并且使用深度复制和酸洗.酸洗的事情主要是由多处理机制来完成的.

This is problematic for me, because I work on a very object-oriented project in which I reference instance methods, and there's use of both deepcopying and pickling. The pickling thing is done mostly by the multiprocessing mechanism.

什么是解决这个问题的好方法?我对复制问题做了一些丑陋的解决方法，但是我正在为这两个问题寻找更好的解决方案.

What would be a good way to solve this? I did some ugly workaround to the copying issue, but I'm looking for a nicer solution to both problems.

有人有什么建议吗?

更新:

我的用例:我有一个很小的事件系统.每个事件都有一个 .action 属性，该属性指向它应该触发的函数，有时该函数是某个对象的实例方法.

My use case: I have a tiny event system. Each event has an .action attribute that points to a function it's supposed to trigger, and sometimes that function is an instance method of some object.

解决方案

您也许可以使用 copy_reg.pickle.在 Python 2.6 中:

You might be able to do this using copy_reg.pickle. In Python 2.6:

import copy_reg
import types

def reduce_method(m):
    return (getattr, (m.__self__, m.__func__.__name__))

copy_reg.pickle(types.MethodType, reduce_method)

这不存储方法的代码，只是它的名字；但这在常见情况下可以正常工作.

This does not store the code of the method, just its name; but that will work correctly in the common case.

这使得酸洗和复制都可以工作！

This makes both pickling and copying work!

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