[Python-Dev] Deprecation policy

[Antoine Pitrou]

On Mon, 24 Oct 2011 15:58:11 +0300
Ezio Melotti <ezio.melotti at gmail.com> wrote:
> 
> I suggest to follow the following process:
>    1) deprecate something and add a DeprecationWarning;
>    2) decide how long the deprecation should last;
>    3) use the deprecated-remove[1] directive to document it;
>    4) add a test that fails after the update so that we remember to 
> remove it[2];

This sounds like a nice process.

> PendingDeprecationWarnings:
> * AFAIK the difference between PDW and DW is that PDW are silenced by 
> default;
> * now DW are silence by default too, so there are no differences;
> * I therefore suggest we stop using it, but we can leave it around[3]

Agreed as well.
 
> [3]: we could also introduce a MetaDeprecationWarning and make 
> PendingDeprecationWarning inherit from it so that it can be used to 
> pending-deprecate itself.  Once PendingDeprecationWarning is gone, the 
> MetaDeprecationWarning will become useless and can then be used to 
> meta-deprecate itself.

People may start using MetaDeprecationWarning to deprecate their
metaclasses. It sounds wrong to deprecate it.

Regards

Antoine.