On Fri, 2022-03-18 at 09:35 -0700, Guido van Rossum wrote: > The motivation has been explained already.
In this thread? > What on earth did your test do that got a speedup by using sets? Was > it repeatedly checking whether a variable was in a slot? The other > thing this does is rearrange the order in which slots appear from run > to run (since set order is affected by hash randomization) and you > might have gotten lucky with a popular attribute being moved to the > front, where it's more likely to be in the memory cache already > (cache lines being 64 bytes and pointers being 8 bytes nowadays). I created objects in a tight loop, populating attributes, noting the elapsed time. > I agree that dicts are a use case to preserve. > > On Fri, Mar 18, 2022 at 08:59 Paul Bryan <pbr...@anode.ca> wrote: > > You've proposed a "what", but I don't see a "why". > > > > Indeed, it will break some code. > > > > I've been (currently legally) expressing __slots__ as sets, which > > is arguably more consistent with its purpose, and in testing > > appeared to perform better than tuples. > > > > So, I would request that you amend the allowed types to include > > sets. > > > > Also, people are using dicts to provide docstrings on attributes, > > so that would need to be addressed as well. > > > > On Fri, 2022-03-18 at 11:42 +0200, Serhiy Storchaka wrote: > > > 18.03.22 11:29, Serhiy Storchaka пише: > > > > It will break some code (there are 2 occurrences in the stdlib > > > > an 1 in > > > > scripts), but that code can be easily fixed. > > > > > > Actually it will break more code, because initializing __slots__ > > > with a > > > list is pretty common. Maybe restrict it to tuple or list? But > > > having an > > > immutable __slots__ may be more reliable. > > > > > > _______________________________________________ > > > Python-Dev mailing list -- python-dev@python.org > > > To unsubscribe send an email to python-dev-le...@python.org > > > https://mail.python.org/mailman3/lists/python-dev.python.org/ > > > Message archived at > > > https://mail.python.org/archives/list/python-dev@python.org/message/HCZHJN2LSD2NXFLSFAO7VVOMEZRTLDBQ/ > > > Code of Conduct: http://python.org/psf/codeofconduct/ > > > > > > _______________________________________________ > > Python-Dev mailing list -- python-dev@python.org > > To unsubscribe send an email to python-dev-le...@python.org > > https://mail.python.org/mailman3/lists/python-dev.python.org/ > > Message archived at > > https://mail.python.org/archives/list/python-dev@python.org/message/6AKHUOVUQ2SQRPE4HAGWAEW2VYRKPFCL/ > > Code of Conduct: http://python.org/psf/codeofconduct/
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