[Python-Dev] New Import Hooks PEP, a first draft (and req. for PEP #)

[Just van Rossum]

Neil Schemenauer wrote:

> I only had time to skim this PEP.  Currently I am using import hooks
> to load PTL modules (like .py modules but they have a different
> extension and need a different compiler).  Most of the discussion has
> focused on loading .py modules from places other than filesystems.  I
> was afraid my use case would not get addressed (iu.py doesn't really
> work, ihooks.py does).  It looks like the hooks proposed by this PEP
> are sufficent for my needs.

Interesting use case! I wish I had known about it earlier. Can you point
me to your code using ihooks, if it's available?

I'm actually not so sure the new hook mechanism solves all your problems
as well as it could/should. I assume these special modules simply live
on sys.path, intermixed with "regular" modules? This would mean you
specifically need to extend the builtin sys.path/pkg.__path__ find/load
logic, which is something the PEP doesn't cater for (yet). If the
special modules live in a special folder, things are easier. Also:
special modules will not work when packaged in a zip file (zipimport
doesn't come *close* to transparently replacing the file system). If you
compile to straight .py[co] (as I assume) and put those in the zip
archive, you should be fine, though.

This also touches on the modulefinder-like-tools-issue. Your hook should
ideally support the get_code(fullname) method, so that packaging tools
will be able to deal with it more or less transparently. Obviously the
hook need to be installed when running modulefinder-like-tools. (Hmm,
this suggests that an external hook registry might be handy, perhaps a
*.pth-like trick...)

Just