[Python-Dev] recursive closures - reference leak

Hrvoje Niksic hrvoje.niksic at avl.com
Tue Dec 8 14:52:06 CET 2009

Kristján Valur Jónsson wrote:
> The problem with this is that once you have called factorial() once, you 
> end up with a recursive cycle.  „factorial“ has become a cell object, 
> referencing the „helper“ function, which again refers to the outer cell 
> object.  This requires „gc“ to clean up.  Also, it is entirely 
> non-obvious.  the problem becomes worse if the inner function also 
> refers to some large, temporary variable, since it will get caught up in 
> the reference loop.

What problem are you referring to?  Python has a gc exactly to deal with 
situations like this one.  Surely you are aware that the cycle collector 
is invoked automatically without requiring user intervention.  What 
specific issue are you trying to work around?

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