My understanding is that if there is a system Python, you shouldn't
change it. Ever.
Huge, big, honkin' +1 from me on that. Besides, for a system Python,
you want your distribution to manage packages, not setuptools,
otherwise you confuse -- and probably break -- your system.
I find this discussion fascinating. I install new packages into my
system Python all the time, with "/usr/bin/python setup.py install",
and that includes setuptools. I've got PIL, ReportLab, Twisted, Xlib,
appscript, docutils, email-4.0.1, fuse, PyLucene, medusa, mutagen,
roman, setuptools, and SSL installed in the Leopard machine I'm
writing from. They don't wind up in
/System/Library/.../site-packages/, they wind up in
/Library/Python/2.5/site-packages/, which is sort of the right place,
from an Apple point of view. I do this on lots of Macs -- I've got a
regular posse of them at work. And I've never had any problems with
it.
I agree that there are some things I'd be very wary of installing into
the system Python, like PyObjC, and Zope. Usually, I don't install
anything which appears to already be there.