[Python-Dev] advice needed: best approach to enabling "metamodules"?

[Steven D'Aprano]

On Sun, Nov 30, 2014 at 11:07:57AM +1300, Greg Ewing wrote:
> Nathaniel Smith wrote:
> >So pkgname/__new__.py might look like:
> >
> >    import sys
> >    from pkgname._metamodule import MyModuleSubtype
> >    sys.modules[__name__] = MyModuleSubtype(__name__, docstring)
> >
> >To start with, the 'from
> >pkgname._metamodule ...' line is an infinite loop,
> 
> Why does MyModuleSubtype have to be imported from pkgname?
> It would make more sense for it to be defined directly in
> __new__.py, wouldn't it? Isn't the purpose of separating
> stuff out into __new__.py precisely to avoid circularities
> like that?

Perhaps I'm missing something, but won't that imply that every module 
which wants to use a "special" module type has to re-invent the wheel?

If this feature is going to be used, I would expect to be able to re-use 
pre-written module types. E.g. having written "module with properties" 
(so to speak) once, I can just import it and use it in my next project.


-- 
Steven