isdataclass() testing for instance-ship does sound like a bug magnet to me.
If isdataclassinstance() is too long (that's understandable), how about isdatainstance()? Regards Antoine. On Wed, 29 Nov 2017 17:02:21 -0800 Guido van Rossum <gu...@python.org> wrote: > On Wed, Nov 29, 2017 at 3:51 PM, Carl Meyer <c...@oddbird.net> wrote: > > > On 11/29/2017 03:26 PM, Eric V. Smith wrote: > > > I've posted a new version of PEP 557, it should soon be available at > > > https://www.python.org/dev/peps/pep-0557/. > > > > > > The only significant changes since the last version are: > > > > > > - changing the "compare" parameter to be "order", since that more > > > accurately reflects what it does. > > > - Having the combination of "eq=False" and "order=True" raise an > > > exception instead of silently changing eq to True. > > > > > > There were no other issues raised with the previous version of the PEP. > > > > Not quite; I also raised the issue of isdataclass(ADataClass) returning > > False. I still think that's likely to be a cause of bug reports if left > > as-is. > > > > I tried to look up the discussion but didn't find much except that you > flagged this as an issue. To repeat, your concern is that isdataclass() > applies to *instances*, not classes, which is how Eric has designed it, but > you worry that either through the name or just because people don't read > the docs it will be confusing. What do you suppose we do? I think making it > work for classes as well as for instances would cause another category of > bugs (confusion between cases where a class is needed vs. an instance > abound in other situations -- we don't want to add to that). Maybe it > should raise TypeError when passed a class (unless its metaclass is a > dataclass)? Maybe it should be renamed to isdataclassinstance()? That's a > mouthful, but I don't know how common the need to call this is, and people > who call it a lot can define their own shorter alias. > _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
