[stdlib-sig] standardizing the deprecation policy (and how noisy they are)

Brett Cannon brett at python.org
Sat Nov 14 01:23:23 CET 2009

I asked Guido and he has made his call: DeprecationWarning will be
silent by default. I have started http://bugs.python.org/issue7319 to
track the work. As of right now it has a patch against trunk to add
the silencing to the warnings filter by default. Still need to come up
with the proper doc changes before it can be committed on trunk and
py3k (probably the tutorial and warnings module; anywhere else?).

On Sun, Nov 8, 2009 at 13:26, Brett Cannon <brett at python.org> wrote:
> During the moratorium PEP discussions Guido said he wanted to quiet
> down deprecation warnings. I see there being two options on this.
> One is to keep things as is, but to require two releases with
> PendingDeprecationWarning so there are three years of
> silent-by-default warnings to update your code. But that last release
> before removal came would still be noisy.
> The other option is to simply have all warnings filtered out by
> default. We could alter -W so that when it is used w/o an argument it
> turns to what is currently the default behaviour (or even turn all
> warnings which is more than what happens now). This will require that
> people proactively check for warnings when updating for compatibility,
> else they will eventually use a Python release where there code will
> simply break because something changed. This route means we do not
> have to specify any deprecation policy right now (that would be a
> separate discussion).
> Channeling Guido he is after the latter, but a general discussion
> would still be good since he didn't explicitly say what he was after
> other than to quiet down warnings.
> -Brett

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