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

[Benjamin Peterson]

2009/7/23 Brett Cannon <brett at python.org>:
>
>
> 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).


I didn't realize None had other semantics attached to it. (Imagine
that dealing with import!) +1 for making it simply indicate an
ImportError.



-- 
Regards,
Benjamin