[Python-Dev] recursive closures - reference cycle

Kristján Valur Jónsson kristjan at ccpgames.com
Wed Dec 9 13:03:52 CET 2009

> -----Original Message-----
> From: python-dev-bounces+kristjan=ccpgames.com at python.org
> [mailto:python-dev-bounces+kristjan=ccpgames.com at python.org] On Behalf
> Of Greg Ewing
> Sent: 8. desember 2009 22:09
> To: python-dev at python.org
> Subject: Re: [Python-Dev] recursive closures - reference cycle
> You could use a class:

Yes, and a number of different workarounds.  That's not really the issue.  The issue is that what looks like a perfectly safe idiom (calling a function recursively) happens to create a reference cycle if that function is a closure.
This is a non-obvious "gotcha" that I must now educate my team about.

Note that at least parts of the library strive to avoid reference cycles even though "gc" exists.  An example being xlm.minidom.Document.unlink()



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