[Python-Dev] Proposal to revert r54204 (splitext change)

[Phillip J. Eby]

At 08:30 AM 3/15/2007 +1100, Delaney, Timothy (Tim) wrote:
>Phillip J. Eby wrote:
>
> > In addition to being made in the face of controversy and opposition,
> > this
> > change is an alteration to *documented and tested* behavior and thus
> > cannot reasonably be considered a mere bug fix.
>
>FWIW, I support Phillip on this. There can be no question that the old 
>behaviour was expected.
>
>IMO this is just gratuitous breakage. The only fix that shold be made is 
>to the splitext documentation to match the docstring.
>
>A change to the documented behaviour should require a __future__ import 
>for at least one version. That's even assuming that the change is 
>desireable (I don't believe so). We have multiple anecdotes of actual, 
>existing code that *will* break with this change. So far I haven't seen 
>any actual code posted that is currently broken by the existing behaviour.

FWIW, I think that, were we writing splitext() *now*, we should go with the 
proposed behavior.  It's reasonable and justifiable even on Windows (even 
though Windows Explorer agrees with the current splitext() behavior.)

But, that doesn't actually have any bearing on the current discussion, 
since splitext()'s behavior is existing and documented.

Certainly, there *is* code that's broken by the existing behavior -- 
otherwise the patch would never have been submitted in the first 
place.  However, that doesn't automatically make it a Python bug, 
especially if the existing behavior is documented and covered by regression 
tests.

I just want to clarify this point, because I don't wish to enter another 
round of discussion about the merits of one behavior or the other: the 
merits one way or the other are pretty much irrelevant to the policy issue 
at hand.