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From: Gregory Ewing <greg.ewing@canterbury.ac.nz>
Newsgroups: comp.lang.python
Subject: Re: Design thought for callbacks
Date: Tue, 24 Feb 2015 18:20:29 +1300
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Xref: csiph.com comp.lang.python:86293

Cem Karan wrote:
> I tend to structure my code as a tree or DAG of objects.  The owner refers to
> the owned object, but the owned object has no reference to its owner.  With
> callbacks, you get cycles, where the owned owns the owner.

This is why I suggested registering a listener object
plus a method name instead of a callback. It avoids that
reference cycle, because there is no long-lived callback
object keeping a reference to the listener.

-- 
Greg