Python leaks in cyclic garbage collection

Steven D'Aprano steve+comp.lang.python at
Sat Feb 19 00:40:41 EST 2011

On Fri, 18 Feb 2011 20:49:09 -0800, Chris Rebert wrote:

> And following the pointer to gc.garbage's docs:
> : "Objects that have
> __del__() methods and are part of a reference cycle ***cause the entire
> reference cycle to be uncollectable*** [...] Python doesn’t collect such
> cycles automatically because, in general, it isn’t possible for Python
> to guess a safe order in which to run the __del__() methods. [...] It’s
> generally better to avoid the issue by not creating cycles containing
> objects with __del__() methods"

Another solution is to manually break the cycle, perhaps by providing a 
"close" method, and requiring the caller to use it.


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