[Python-Dev] Document None values in sys.modules?

[Brett Cannon]

On Thu, Jul 23, 2009 at 19:38, Benjamin Peterson <benjamin at python.org>wrote:

> 2009/7/23 Brett Cannon <brett at python.org>:
> > None in Python 3.1 is really useless in terms of its semantics in
> relative
> > imports; importlib doesn't support it and still passes as __import__ (at
> > least last time I ran the test suite that way). I thought we had agreed a
> > while back that supporting None was not warranted in Python 3.0?
> Otherwise I
> > will do whatever work is necessary for this to happen.
>
> I think it's still nice for the rare cases where you need to trick a
> module into thinking another one doesn't exist.


But None does not strictly mean "I don't exist". None is supposed to trigger
an another import attempt for the module with a top-level name. It's that
extra import trigger that has no real use in 3.0 and just complicates import
semantics (IMO) needlessly. If you want a module to not exist then you
either stick something else in (e.g. '42') or we remove the special
semantics for None (which I thought we had).

-Brett
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-dev/attachments/20090723/2941b0a2/attachment.htm>