[Python-Dev] Towards a Python based import scheme
Gordon McMillan
gmcm@hypernet.com
Thu, 16 Sep 1999 13:38:03 -0400
Jim Ahlstrom wrote:
> As a result of all this import discussion I am a bit worried that
> the python library *.pyl file format may not be powerful enough.
> I have always thought in terms of unique top-level names and a
> format which supports import of modules and packages. But this
> does not support the full functionality of PYTHONPATH. For
> example, PYTHONPATH can (and is) used to select the correct
> plat-* directory files. And the format may not support Jim
> Fulton's fancy local import scheme. And what if someone invents
> a third thing to import besides a module or a package?
> PYTHONPATH is not going away nor should it.
The central idea of imputil is that an importer is responsible for
one little chunk of turf. If the desired module / package isn't
"his", he just passes the request on to the next element in the
chain.
So I don't think there's a need for one canonical do-everything
importer (or archive format). PYTHONPATH is outside any
particular importer. Effectively, you can use a chain of
importers to replace PYTHONPATH. So the platform specific
modules might be found by one particular importer. In other
words, I think it's more effective to specialize individual
importers and chain them up than it is to try to create an
overly-generalized importer.
- Gordon