Now I understand what you're getting at; I didn't realize that you were aiming at the possible distinction between 3 and 3.1. Yes, this is what bothered me and prompted my original posting. Python 3.1 goes into the same framework as the 2.x versions.

Incidentally, I did find that in /usr/local/bin (where I had not thought to look) there are the following:

python3.1, a link to the framework python3.1
pythonw3.1, a link to the framework pythonw3.1

python3, a link to a framework python3, which is an extra copy (not a link) to the framework python3.1
pythonw3, a link to a framework pythonw3, which is a link to the framework python3.1

This looks to me pretty contorted, although I suppose the goal was to let people either run "python" (their most recent Python 2.x) or run "python3" (their most recent Python 3.x).

A somewhat related example of confusion is that on Ubuntu 10.10 there is a shadowy existence for some python3 that has its own lib folder, in parallel to python3.1; the python3 doesn't seem to be simply an alias for python3.1.