Postgresql – How to install psycopg2 for multiple python interpreters on a CentOS box

Unfortunately, you cannot remove Python 2.4 from RHEL5, unless you're able to remove (or patch) dozens of Python scripts that only work with 2.4, not 2.6. You can easily install 2.6 in parallel with 2.4 (as you already know), but removing 2.4 is "major surgery". You can certainly try, but most users/operators just don't bother.

As another poster noted, '/usr/bin/python26' is in your default PATH, just like '/usr/bin/python'. On the command line, you can just call 'python26' instead of 'python'. In your 2.6-specific scripts/programs, you can replace your she-bang lines with '#!/usr/bin/python26'.

Handling 2.6-only modules is a bit harder. You'll need to move them from '/usr/lib/python/...' to '/usr/lib/python26/...'. If you're lucky, somebody may have already packaged a variant specifically for Python 2.6 on RHEL5 with the paths changed, or you can modify and rebuild existing RPMs, yourself.

The problem is that the transition from Python 2.4 to 2.6 introduced a few backward-incompatibilities. So a lot of scripts authored with 2.4 in mind won't run properly under 2.6 without some patching. (There are people who claim that 2.6 IS backwards compatible... it's close, but not 100%.)

Recent Fedora releases and the RHEL6 beta ship more advanced Python versions (2.5+), along with updates to dozens (possibly hundreds) of Python scripts, too. But Red Hat decided to keep its EL5 branch on Python 2.4, probably due to the risk of breaking any Python 2.4-only scripts running on clients' machines. (This is a pretty standard practice for a long-term-stable distro series like RHEL.)

export PYTHONPATH=/opt/python2.6
export PATH=/opt/python2.6/bin:$PATH

And then configure / make / make install the python-rsvg module (from gnome-python-desktop), and it should just work.

If you want just the rsvg module without the rest, you can use ./configure --disable-allbindings --enable-rsvg.

And make sure you have the librsvg2-devel package installed, or else the module won't build no matter how many --enables you give. :)

Update:

Clearly something is going wrong at the update #2 stage above, where ./configure tells you that it's doing something other than what it says it's going to. Particularly, the metacity bindings are called out in the configure help as being poorly maintained.

I'm not quite sure what's wrong -- is there something helpful in the (long) output from configure? Alternately, you could try to use waf instead of configure/make. Run:

./waf configure --enable-modules=rsvg
./waf
./waf install

(Noting that --disable-allbindings isn't necessary.)

The first line should tell you that only rsvg will be built.

Further Update:

With this approach, you're gonna need pygtk and pycairo built into your /opt/python2.6 tree. That may be why the configure is failing.