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Re: Two aces up Python's sleeve

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The wiked brain of ChatGPT gives me a lead:

PEP 659
Storing data caches before the bytecode.

Maybe its an effect of constant folding
and constant pooling by the compiler?

Mild Shock schrieb:
> 
> For example this article:
> 
> https://www.codementor.io/@arpitbhayani/python-caches-integers-16jih595jk
> 
> about the integer singletons claims:
> 
>  >>> x, y = 257, 257
>  >>> id(x) == id(y)
> False
> 
> But on Windows my recent CPython doesn't do that:
> 
> Python 3.14.0a1 (tags/v3.14.0a1:8cdaca8, Oct 15 2024, 20:08:21)
>  >>> x, y = 257, 257
>  >>> id(x) == id(y)
> True
> 
> Mild Shock schrieb:
>> Hi,
>>
>> In Java its possible to work this way
>> with the Integer datatype, just call
>> Integer.valueOf().
>>
>> I am not sure whether CPython does the
>> same. Because it shows me the same behaviour
>> for small integers that are more than
>>
>> only in the range -128 to 128. You can try yourself:
>>
>> Python 3.14.0a1 (tags/v3.14.0a1:8cdaca8, Oct 15 2024, 20:08:21)
>>  >>> x,y = 10**10, 10**9*10
>>  >>> id(x) == id(y)
>> True
>>
>> Maybe the idea that objects have an address
>> that can be accessed via id() has been abandoned.
>> This is already seen in PyPy. So maybe we
>>
>> are falsly assuming that id() gives na object address.
>>
>> Greg Ewing schrieb:
>>> On 8/11/24 3:04 am, Mild Shock wrote:
>>>> This only works for small integers. I guess
>>>> this is because tagged pointers are used
>>>> nowadays ?
>>>
>>> No, it's because integers in a certain small range are cached. Not 
>>> sure what the actual range is nowadays, it used to be something like 
>>> -5 to 256 I think.
>>>
>>> BTW you have to be careful testing this, because the compiler 
>>> sometimes does constant folding, so you need to be sure it's actually 
>>> computing the numbers at run time.
>>>
>>
> 

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Re: Two aces up Python's sleeve Mild Shock <janburse@fastmail.fm> - 2024-11-06 17:27 +0100
  Re: Two aces up Python's sleeve Annada Behera <annada@tilde.green> - 2024-11-07 12:55 +0530
    Re: Two aces up Python's sleeve Mild Shock <janburse@fastmail.fm> - 2024-11-07 15:04 +0100
      Re: Two aces up Python's sleeve Greg Ewing <greg.ewing@canterbury.ac.nz> - 2024-11-08 11:15 +1300
        Re: Two aces up Python's sleeve dn <PythonList@DancesWithMice.info> - 2024-11-08 13:07 +1300
        Re: Two aces up Python's sleeve Mild Shock <janburse@fastmail.fm> - 2024-11-08 01:25 +0100
          Re: Two aces up Python's sleeve Mild Shock <janburse@fastmail.fm> - 2024-11-08 01:29 +0100
            Re: Two aces up Python's sleeve Mild Shock <janburse@fastmail.fm> - 2024-11-08 01:47 +0100
    Re: Two aces up Python's sleeve (Posting On Python-List Prohibited) Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-11-08 01:10 +0000
      Re: Two aces up Python's sleeve (Posting On Python-List Prohibited) Mild Shock <janburse@fastmail.fm> - 2024-11-08 02:40 +0100
        Re: Two aces up Python's sleeve (Posting On Python-List Prohibited) dn <PythonList@DancesWithMice.info> - 2024-11-09 08:09 +1300
          Re: Two aces up Python's sleeve (Posting On Python-List Prohibited) Mild Shock <janburse@fastmail.fm> - 2024-11-08 20:49 +0100
        Re: Two aces up Python's sleeve (Posting On Python-List Prohibited) Thomas Passin <list1@tompassin.net> - 2024-11-08 17:00 -0500

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