[Python-Dev] When to remove deprecated stuff (was: Deprecating the formatter module)

[R. David Murray]

On Thu, 15 Aug 2013 11:22:14 +0200, Antoine Pitrou <solipsis at pitrou.net> wrote:
> On Thu, 15 Aug 2013 11:16:20 +0200
> Victor Stinner <victor.stinner at gmail.com> wrote:
> > 2013/8/15 Antoine Pitrou <solipsis at pitrou.net>:
> > > We don't have any substantial change in store for an eventual "Python
> > > 4", so it's quite a remote hypothesis right now.
> > 
> > I prefered the transition between Linux 2 and Linux 3 (no major
> > change, just a "normal" release except the version), rather than the
> > transition between KDE 3 and KDE 4 (in short, everything was broken,
> > the desktop was not usable).
> > 
> > I prefer to not start a list of things that we will make the
> > transition from Python 3 to Python 4 harder. Can't we do small changes
> > between each Python release, even between major versions?
> 
> That's exactly what I'm saying.
> But some changes cannot be made without breakage, e.g. the unicode
> transition. Then it makes sense to bundle all breaking changes in a
> single version change.

A number of us (I don't know how many) have clearly been thinking about
"Python 4" as the time when we remove cruft.  This will not cause any
backward compatibility issues for anyone who has paid heed to the
deprecation warnings, but will for those who haven't.  The question
then becomes, is it better to "bundle" these removals into the
Python 4 release, or do them incrementally?

If we are going to do them incrementally we should make that decision
soonish, so that we don't end up having a whole bunch happen at once
and defeat the (theoretical) purpose of doing them incrementally.

(I say theoretical because what is the purpose?  To spread out the
breakage pain over multiple releases, so that every release breaks
something?)

--David