[Python-Dev] PEP 3003 - Python Language Moratorium

Nick Coghlan ncoghlan at gmail.com
Fri Nov 6 10:35:46 CET 2009

Brett Cannon wrote:
> On Thu, Nov 5, 2009 at 19:23, Guido van Rossum <guido at python.org> wrote:
>> On Thu, Nov 5, 2009 at 3:35 PM, Brett Cannon <brett at python.org> wrote:
>>> On Thu, Nov 5, 2009 at 15:26, Guido van Rossum <guido at python.org> wrote:
>>>> I have come to the conclusion that there are better ways to
>>>> pre-announce that a module is going to disappear instead of
>>>> deprecation warnings.
>>> What exactly are those better ways? Document as deprecated only?
>> Sorry, I have an existence proof, but no construction. :-)
>> Ideas welcome. Silent deprecations, loud documentation, biweekly home
>> visits, whatever, as long as it doesn't log a message by default.
> Well, one option is to come up with the equivalent of -3, but for all
> warnings; the antithesis of -W. And obviously glaring deprecation
> warnings in the docs (removal has been discussed but always shot down
> as someone who comes across old code might still need docs for it).

For a PEP 3003-specific solution, we could adopt a policy that we will
add only Pending Deprecation warnings during the moratorium period. The
actually deprecation clock would then only start in the first release
after the moratorium ends (i.e. full Deprecation Warning in that
release, removal in the following release).

No doubt some third party developers would end up being shocked by a
raft of warnings at that point, but those that are paying more attention
would get a chance to clean up the warnings without alarming their users.

Longer term, a solution may be to extend the standard deprecation period
one release and make pending deprecation warnings required rather than
optional. That way, on the ball developers would have a full release to
quash deprecation warnings before their users encountered them by default.

That is:

  Release X.Y: deprecated in docs, pending deprecation in code
  Release X.Y+1: deprecated in code
  Release X.Y+2: removed in code and docs

(Or we could just make that the policy now and not do anything specific
in relation to the moratorium and the standard library)


Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia

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