[Python-Dev] Process to remove a Python feature

[Serhiy Storchaka]

04.05.18 20:57, Matthias Bussonnier пише:
> But when I hit a DeprecationWarning message there is one crucial piece of
> information missing most of the time: Since which version number it's 
> deprecated
> (and sometime since when the replacement is available could be good if 
> overlap
> between functionality there was).

I think the information about since which version number it will be 
removed is more useful. Different cases need different deprecation 
periods. The more common the case, the longer deprecation period should 
be. Some recently added warnings contain this information.

Ideally any deprecated feature should have a replacement, and this 
replacement should be available in at least one version before adding 
the deprecation warning.

X.Y: added a replacement

X.Y+1: added a deprecation warning. Many users need to support only two 
recent versions and can move to using the replacement now.

X.Y+3 (or X.Y+2): removed the deprecated feature. Versions older than 
X.Y should grew out of use at that moment.