[Python-Dev] Relative Package Imports

Jim Fulton jim@digicool.com
Wed, 15 Sep 1999 15:34:08 -0400


"Barry A. Warsaw" wrote:
> 
>     JF> Zope products are python packages installed as sub-packages of
>     JF> the Zope 'Products' packages.  Products are generally
>     JF> self-contained.  If they need anything that's not part of
>     JF> standard Python or standard Zope, they need to include it or
>     JF> install what they need in a sub-package of another Zope
>     JF> package, 'Shared'.
> 
> Jim, from your description, it sounds like Zope should be putting both
> the `Shared' and possibly `Products' directories on sys.path.

It actually does now, although that is bad.  What if some future
python distribution has a Products package? Or a Products.py?

A product is actually a sub-package of Products. Even if Products 
was not a package, the Product would be and gadfly and kjParsong would
be sub-packages.  There is a similar issue with Shared, since Shared
software is organized by organization, as in 'Shared.DC.ZRDB'.

> Maybe
> it does and I'm still missing your point.

The point is that stuffing arbitrary things into a single global
name space is bad. That's why packages were invented.  Unless 
packages can be effectively nested, you haven't gained anything but time.
 
> However if they are not, then wouldn't this solve your problem? 

No, see above.

> A
> user would drop the kjParsing directory into Shared, and then all the
> import kjParsing.kjParser statements would Just Work.

But then they'd be dumping kjParsing into the global package namespace.
Eventually, there will be collisions.

Jim

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