[Python-Dev] PEP 408 -- Standard library __preview__ package

[Eric Snow]

On Sat, Jan 28, 2012 at 3:02 PM, Antoine Pitrou <solipsis at pitrou.net> wrote:
> There are many reasons to import a module, such as viewing its
> documentation. And the warning will trigger if the import happens in
> non-user code, such as a library; or when there is a fallback for the
> module not being present. People usually get annoyed by intempestive
> warnings which don't warn about an actual problem.

As an alternative, how about a __preview__ or __provisional__
attribute on modules that are in this provisional state?  So just add
that big warning to the docs, as Guido suggested, and set the
attribute as a programmatic indicator.  Perhaps also add
sys.provisional_modules (or wherever) to explicitly give the full list
for the current Python version.

-eric