[Python-Dev] subclasses() return order (original) (raw)

Łukasz Langa lukasz at langa.pl
Sat May 25 15:49:04 CEST 2013


On 25 maj 2013, at 15:45, Antoine Pitrou <solipsis at pitrou.net> wrote:

On Sat, 25 May 2013 15:26:58 +0200 Antoine Pitrou <solipsis at pitrou.net> wrote:

On Sat, 25 May 2013 06:23:56 -0700 Eli Bendersky <eliben at gmail.com> wrote: On Sat, May 25, 2013 at 6:18 AM, Antoine Pitrou <solipsis at pitrou.net> wrote:

Hello, In http://bugs.python.org/issue17936, I proposed making tpsubclasses (the internal container implementing object.subclasses) a dict. This would make the return order of subclasses completely undefined, while it is right now slightly predictable. I have never seen subclasses actually used in production code, so I'm wondering whether someone might be affected by such a change. Regards Personally I never used it, but it's now explicitly documented as returning a list. Not sure what's the right thing to do here, but perhaps returning an OrderedDict can eliminate the order problem? It would still return a list. I guess I should explain myself more clearly: subclasses() already computes its result on-the-fly (it must weed out dead weakrefs) (*). So the visible behaviour of subclasses wouldn't change, except for ordering.

+1

Makes sense to me. As currently defined, you cannot rely on the item order anyway.

-- Best regards, Łukasz Langa

WWW: http://lukasz.langa.pl/ Twitter: @llanga IRC: ambv on #python-dev

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