Environmental variable $PYTHONPATH

[sue]

I think any app installed under PYTHONHOME is automatically
visible. (I set python up two years ago and haven't had to
touch it. :-)

These both default to your python install dir.
I also put an apps.pth file in the python install directory.

Then I filter the output from dir into it, with one of two
conventions for the filter:

1. that every subdirectory is an app.
2. Or I have a "site_pkg" directory to match the UNIX
structure and apps are under that.

Either works.  And the filter is in Python.  Actually, I
think it's glob.glob() now, instead of dir.

You can read the gory details in site.py in the standard
library.

On the other hand, at least you can read it, unlike
registry-based stuff.

Sue.