[Python-Dev] PEP, take 2: Exception Reorganization for Python 3.0

[Brett Cannon]

On 8/2/05, Raymond Hettinger <python at rcn.com> wrote:
> The Py3.0 PEPs are a bit disconcerting.  Without 3.0 actively in
> development, it is difficult to get the participation, interest, and
> seriousness of thought that we apply to the current release.  The PEPs
> may have the effect of prematurely finalizing discussions on something
> that still has an ethereal if not pie-in-the-sky quality to it.  I would
> hate for 3.0 development to start with constraints that got set in stone
> before the project became a reality.
> 

I don't view this PEP (nor any other PYthon 3000 PEP) as set in stone
until we are one or two versions away from Python 3.0 .  I view these
PEPs as just provoking discussion and getting the ball rolling now
instead of rushing to get it done when it does come time to start
thinking about these things.  Even if we get everyone to agree on this
PEP I still won't consider it finalized until there is one more round
of discussion just before we start implementing for Python 3.0 .

> With respect to exception re-organization, the conversation has been
> thought provoking but a little too much of a design-from-scratch
> quality.  Each proposed change needs to be rooted in a specific problem
> with the current hierarchy (i.e. what use cases cannot currently be
> dealt with under the existing tree).  Setting a high threshold for
> change will increase the likelihood that old code can be easily ported
> and decrease the likelihood of either throwing away previous good
> decisions or adopting new ideas that later prove unworkable.  IOW,
> unless the current tree is thought to be really bad, then the new tree
> ought to be very close to what we have now.
> 

So are you saying that the renaming is bad, or the whole reorg?  It
seems everyone agrees with the moving of the control flow exceptions
and CriticalException, although the renamings might just me wishing
for it.

-Brett