[Distutils] imp.find_modules and namespaces

[Alessandro Dentella]

On Mon, Feb 11, 2013 at 04:11:38PM -0500, PJ Eby wrote:
> On Mon, Feb 11, 2013 at 11:40 AM, Alessandro Dentella <sandro at e-den.it> wrote:
> >
> > I believe that this issue belongs to this list, please let me know if I'm
> > wrong.
> >
> > Suppose I have 2 packages:
> >
> >   jmb.foo
> >   jmb.bar
> >
> > distributed separately. Each has in jmb's __init__ a standard:
> >
> >
> >   __import__('pkg_resources').declare_namespace(__name__)
> >
> > or
> >
> >   from pkgutil import extend_path
> >   __path__ = extend_path(__path__, __name__)
> >
> >
> > I just realized that imp.find_module() will return "fake" values
> >
> >   imp.find_module('jmb', None)
> >
> > may return (a tuple with) the path from the first package or from the
> > second. Many framework will fail to discover commands in the inner module:
> > one is detailed here [1] another is Django way of getting application's
> > commands.
> >
> > I find it misleading to return a value that is not thorohly correct.
> >
> > Is there a workaround? Is the current behaviour considered correct for
> > reasons I don't yet understand?
> 
> Since Python 2.5, the right way to do this is with
> pkgutil.iter_modules() (for a flat list) or pkgutil.walk_packages()
> (for a subpackage tree).
> 
> For your example, if I wanted to find just the subpackages of 'jmb', I would do:
> 
>     import jmb, pkgutil
>     for (module_loader, name, ispkg) in
> pkgutil.iter_modules(jmb.__path__, 'jmb.'):
>         # 'name' will be 'jmb.foo', 'jmb.bar', etc.
>         # 'ispkg' will be true if 'jmb.foo' is a package, false if it's a module

thanks for the answer but this way I need to really import jmb while
imp.find_module doesn't really import it. I *think* that django people
wanted to test if some modules are present w/o importing. If an import
occurs, since I already know the name it should have, it bettere to try that
one directly.


sandro
*:-)

-- 
Sandro Dentella  *:-)
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