[Python-Dev] Type hints -- a mediocre programmer's reaction

[Guido van Rossum]

On Tue, Apr 21, 2015 at 9:47 AM, Antoine Pitrou <solipsis at pitrou.net> wrote:

> On Tue, 21 Apr 2015 09:28:45 -0700
> Guido van Rossum <guido at python.org> wrote:
> > On Tue, Apr 21, 2015 at 12:49 AM, Antoine Pitrou <solipsis at pitrou.net>
> > wrote:
> >
> > > On Mon, 20 Apr 2015 20:43:38 -0400
> > > "R. David Murray" <rdmurray at bitdance.com> wrote:
> > > > +1 to this from me too. I'm afraid that means I'm -1 on the PEP.
> > > >
> > > > I didn't write this in my earlier email because I wasn't sure about
> it,
> > > > but my gut reaction after reading Harry's email was "if type
> annotations
> > > > are used in the stdlib, I'll probably stop contributing".  That
> doesn't
> > > > mean that's *true*, but that's the first time I've ever had that
> > > > thought, so it is probably worth sharing.
> > >
> > > I think it would be nice to know what the PEP means for daily stdlib
> > > development. If patches have to carry typing information each time they
> > > add/enhance an API that's an addition burden. If typing is done
> > > separately by interested people then it sounds like it wouldn't have
> > > much of an impact on everyone else's workflow.
> >
> > This point will be moot until new code appears in the stdlib whose author
> > likes type hints. As I said, we won't be converting existing code to add
> > type hints (I'm actively against that for the stdlib, for reasons I've
> > explained already).
>
> I was thinking of potential stub files. Or are you also putting a ban
> on those for existing stdlib code? Sorry if that has already been
> answered...
>

No ban, but for now the plan is to collect and manage those separately as
part of typeshed. I imagine the typical failure case is where the stubs are
more restrictive than the implementation -- after all if the implementation
becomes *more* restrictive it's breaking backward compatibility. I think
it's okay for the stubs to lag behind like that, so I don't expect pressure
on stdlib contributors. If anything the pressure will be on typeshed.

-- 
--Guido van Rossum (python.org/~guido)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-dev/attachments/20150421/3995fb8c/attachment.html>