[Python-3000] Get rid of Py_FindMethod

[Oren Tirosh]

The primary use of Py_FindMethod was to implement a tp_getattr slot
handler. Now that it has been removed, there is nothing remaining in
the py3k codebase that actually uses the tp_getattr slot!

It has been 12 years since tp_getattro was introduced. Is it time to
finally phase out tp_getattr?

Oren


On Tue, Jul 1, 2008 at 8:06 PM, Guido van Rossum <guido at python.org> wrote:
>
> On Tue, Jul 1, 2008 at 5:37 AM, Amaury Forgeot d'Arc <amauryfa at gmail.com> wrote:
> > http://bugs.python.org/issue3247 complains that with python 3.0, dir()
> > of a SRE_Match object returns an empty list.
> >
> > This type has the particularity to not define a tp_methods; instead,
> > its tp_getattr slot calls Py_FindMethod(match_methods, self, name)
> > where "match_methods" is a PyMethodDef[] array that looks very very
> > similar to a typical tp_methods slot.
> >
> > Py_FindMethod has a trick: when the requested name is "__methods__",
> > it returns the names of the PyMethodDef items.
> >
> > __methods__ has disappeared with python 3.0, and indeed if I enable
> > the "-3" warning flag on python2.6,
> > dir() on a SRE_Match object raises two (!) warnings:
> > __main__:1: DeprecationWarning: __methods__ not supported in 3.x
> > __main__:1: DeprecationWarning: __members__ and __methods__ not supported in 3.x
> >
> > According to previous discussions:
> > http://mail.python.org/pipermail/python-3000/2007-July/008787.html
> > Py_FindMethod is not needed any more in modern modules, and should go away.
> > Note that PyMember_Get has already disappeared, because the few
> > modules using them were deleted...
> >
> > Is it still time for such a change after beta1?
>
> I'd say definitely. This just fell through the cracks.
>
> > There are ~30 occurrences of Py_FindMethod in the code base.
> > Most of the time, it is enough to remove the call, and set the
> > tp_methods members.
>
> Good!
>
> > Another thing: why was traceback.__dir__ added?
> > the current 3.0 produces:
> >>>> dir(b.__traceback__)
> > ['tb_frame', 'tb_lasti', 'tb_lineno', 'tb_next']
> >
> > When I remove the __dir__ method, I get the special methods as well:
> >>>> dir(b.__traceback__)
> > ['__class__', '__delattr__', '__doc__', '__eq__', '__format__',
> > '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__',
> > '__le__', '__lt__', '__ne__', '__new__', '__reduce__',
> > '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__',
> > '__subclasshook__', 'tb_frame', 'tb_lasti', 'tb_lineno', 'tb_next']
> >
> > It's more verbose, but most types have the same list of special
> > members. I suggest to remove it, to enhance consistency (loosing some
> > 2.6 compatibility, but it's python3.0 after all)
>
> Can't tell you why -- looks odd to me too. Hopefully Collin Winter remembers.
>
> --
> --Guido van Rossum (home page: http://www.python.org/~guido/)