Hello. The answer is, I don't know. But I originally replaced my existing Python with 3.1.1. I then had to backtrack because some stuff broke. Nothing in the OS, but adapting every Python script on my HD was not what I wanted to do.
So my Py3 executable is at: /Library/Frameworks/Python.framework/Versions/3.1/bin/python3.1 then symlink to that in folder: /usr/local/bin using command: sudo ln -s /Library/Frameworks/Python.framework/Versions/3.1/bin/ python3.1 /usr/local/bin/python3.1 so that saying: ls /usr/local/bin shows the link to the Py3 folder as: python3.1 -> /Library/Frameworks/Python.framework/Versions/3.1/bin/ python3.1 Now your existing scripts still work on Py 2.6. New scripts invoke Py3 like this: #!/usr/local/bin/python3.1 For Terminal sessions, an alias in your bash_profile puts you in Py3 by default without nasty surprises: alias python=/usr/local/bin/python3.1 You can also create a file at: /Library/Python/3.1/site-packages/sitecustomize.py with a configuration that runs at loadtime, although some things seem to fail. But all in all this system has worked well for me (including CGI) and should be easy to go mainstream once Apple goes to Py3. -- Gnarlie -- http://mail.python.org/mailman/listinfo/python-list