Using Py 1.5.2 libs/mods with Py 2.2 ? (for PyQt)

[Az Tech]

Hello list,

1. I have Red Hat Linux 7.3.

2. Python 1.5.2 came preinstalled with it.

3. Then, either:
    - I installed PyQt 3.1
    OR
    - it was already installed along with RHL 7.2
    (I don't remember which of the above, now, as it
was some time back).

4. Then some days later I installed Python 2.2 from
the RH apps CD.

When I tried to run one of the example PyQt apps
(using Py 2.2), I got an error on the 'import qt'
statement - to the effect that the qt module was not
found.

5. Since I knew that PyQt was installed (by doing an
"rpm -q PyQt" and "rpm -q PyQt-examples", both of
which showed that the respective packages were
installed), I was surprised at the above error. 
(I had not realized at this point, that I had
installed Py 2.2 after installing PyQt 3.1)

6. Doing a 'find / -name "*[Pp][Yy][Qq][Tt]*' showed
the location of the PyQt files - they were installed
in the Python 1.5.2 site-packages directory, not in
that of Py 2.2. 

7. So I switched to Py 1.5.2 and tried running the
examples. Some of them worked, some partly worked and
partly gave some errors. I am not sure if this is due
to a version clash between Py 1.5.2 and the PyQt
version which is 3.1 (and my Qt version is 3.0.3).

8. I can of course uninstall PyQt, and then re-install
it in the Py 2.2 tree; I haven't tried this yet but I
think I should be able to manage it. And I know that
this is probably the right way to do it.

9. However, I may not want to do that just now. 
Generalizing the situation, this led me to wonder
whether is is possible and "officially" recommended to
use one version of Python with the libraries / modules
installed in the site-packages directory of another
version, and if so, what is the way to do it ? Setting
the PYTHONPATH to include that site-packages directory
? Or some other way ? And are there any issues that
may arise as a result of this ? Such as conflicts
between versions of different libraries and the
language, etc. ?

Thanks for any advice.

Az.