[Python-3000] backported ABC

[Guido van Rossum]

You're going to have to do some spelunking in the 3.0 source (because
I don't have time right now :-), but I think 3.0 has some magic that
solves this. I *think* it is done by not inheriting tp_hash unless
tp_richcompare is also inherited. The details are probably in
typeobject.c.

Ask me again tomorrow if you can't figure it out.

--Guido

On 9/3/07, Benjamin Aranguren <baranguren at gmail.com> wrote:
> I am having a problem backporting collections.py/_abcoll.py and would
> like to get your input.
>
> There's one test in test_collections that fails.
>
> class TestOneTrickPonyABCs(unittest.TestCase):
>
>     def test_Hashable(self):
>         # Check some non-hashables
>         non_samples = [list(), set(), dict()]
>         for x in non_samples:
>             self.failIf(isinstance(x, Hashable), repr(x))
>             self.failIf(issubclass(type(x), Hashable), repr(type(x)))
>
> The problem is list, set, dict all has __hash__ function so isinstance
> and issubclass returns true even though none of list, set, and dict
> was registered as a subclass of Hashable.
>
> But, calling x.__hash__() on these types results to a TypeError: list
> objects are unhashable.
>
> Thanks!
>
> On 8/26/07, Benjamin Aranguren <baranguren at gmail.com> wrote:
> > I got it now.  both modules need to be backported as well.  I'm on it.
> >
> > On 8/26/07, Benjamin Aranguren <baranguren at gmail.com> wrote:
> > > No problem.  Created issue 1026 in tracker with a single patch file attached.
> > >
> > > I'm not aware of what changes need to be done with _abcoll.py and
> > > collections.py.  If you can point me to the right direction, I would
> > > definitely like to work on it.
> > >
> > > On 8/26/07, Guido van Rossum <guido at python.org> wrote:
> > > > Thanks!
> > > >
> > > > Would it inconvenience you terribly to upload this all to the new
> > > > tracker (bugs.python.org)? Preferably as a single patch against the
> > > > svn trunk (to use svn diff, you have to svn add the new files first!)
> > > >
> > > > Also, are you planning to work on _abcoll.py and the changes to collections.py?
> > > >
> > > > --Guido
> > > >
> > > > On 8/26/07, Benjamin Aranguren <baranguren at gmail.com> wrote:
> > > > > We copied abc.py and test_abc.py from py3k svn and modified to work with 2.6.
> > > > >
> > > > > After making all the changes we ran all the tests to ensure that no
> > > > > other modules were affected.
> > > > >
> > > > > Attached are abc.py, test_abc.py, and their relevant patches from 3.0 to 2.6.
> > > > >
> > > > > On 8/25/07, Guido van Rossum <guido at python.org> wrote:
> > > > > > Um, that patch contains only the C code for overloading isinstance()
> > > > > > and issubclass().
> > > > > >
> > > > > > Did you do anything about abc.py and _abcoll.py/collections.py and
> > > > > > their respective unit tests? Or what about the unit tests for
> > > > > > isinstance()/issubclass()?
> > > > > >
> > > > > > On 8/25/07, Benjamin Aranguren <baranguren at gmail.com> wrote:
> > > > > > > Worked with Alex Martelli at the Goolge Python Sprint.
> > > > > >
> > > > > > --
> > > > > > --Guido van Rossum (home page: http://www.python.org/~guido/)
> > > > > >
> > > > >
> > > > >
> > > >
> > > >
> > > > --
> > > > --Guido van Rossum (home page: http://www.python.org/~guido/)
> > > >
> > >
> >
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-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)