amauryfa at gmail
Aug 25, 2008, 4:22 AM
Post #2 of 4
(671 views)
Permalink
|
Hello,
2008/8/25 Robert Schuppenies <robert.schuppenies[at]gmail.com>:
> Hi.
>
> Could you please explain to me why some iterators have a tp_traverse
> implementation and others do not? For example tupleiterator has one,
> but none of the dict iterators. Same for set iterators (and possibly
> others). It shows in Python when you use the get_referents function.
>
>>>> t = (1,2,3)
>>>> gc.get_referents(iter(t))
> [(1, 2, 3)]
>>>> s = set([1,2,3])
>>>> gc.get_referents(iter(s))
> []
>>>> d = {1:1, 2:2}
>>>> gc.get_referents(iter(d))
> []
>
> And is it correct that you can rephrase the question to 'why some
> iterators are seen as container objects and others are not'?
Yes, this can lead to some object cycle that are not collected.
See the attached script: a cycle involving a list iterator is
collected by the garbage collector, but a cycle with a dict iterator
is not.
This is worth a bug report IMO.
--
Amaury Forgeot d'Arc
|
cycle.py
