On Thu, Sep 3, 2015 at 9:23 AM, Valentine Sinitsyn
<valentine.sinit...@gmail.com> wrote:
> Hi Armin,
>
> On 25.08.2015 13:00, Armin Rigo wrote:
>>
>> Hi Valentine,
>>
>> On 25 August 2015 at 09:56, Valentine Sinitsyn
>> <valentine.sinit...@gmail.com> wrote:
>>>>
>>>> Yes, I think so. There is a *highly obscure* corner case: __del__
>>>> will still be called several times if you declare your class with
>>>> "__slots__=()".
>>>
>>>
>>> Even on "post-PEP-0442" Python 3.4+? Could you share a link please?
>>
>>
>> class X(object):
>> __slots__=() # <= try with and without this
>> def __del__(self):
>> global revive
>> revive = self
>> print("hi")
>>
>> X()
>> revive = None
>> revive = None
>> revive = None
>
> By accident, I found a solution to this puzzle:
>
> class X(object):
> __slots__ = ()
>
> class Y(object):
> pass
>
> import gc
> gc.is_tracked(X()) # False
> gc.is_tracked(Y()) # True
>
> An object with _empty_ slots is naturally untracked, as it can't create back
> references.
>
> Valentine
>
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That does not make it ok to have del called several time, does it?
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