> May I ask why?

Independence. When you upgrade to RH7, you don't need to worry if all your scripts will run with Python 2.7, they'll still point to your own 2.6. You can decide to upgrade to 2.7 (or not) on your own time. You can do it before or after your migration to RH7; they're independent decisions. Even ignoring Python3, Python occasionally breaks backwards compatibility (the deprecate, warnings, then errors dance). It's nice to control your own situation.

But our programs are internal-use only. So we don't have the same concerns with security updates, ease of deployment to customers, etc., that you may face.

At the facility I work at we're still migrating from Cent5 to Cent6. Cent5 is installed with Python 2.4 (released 2004-11-30, unsupported since 2008-12-19). Thankfully, we're juggling Python 2.5 and 2.6. We rely on a couple pieces of third-party software that include their own Python (2.6 and 2.7).

But even without the third-party software I'd prefer to use a separate install of Python. If there were a few Python scripts there and there, we could probably manage, but managing a large Python codebase would be ridiculous trying to rely on the OS version of Python. Transitions to new OS versions would be way harder, too.

> > I've always considered it bad to use the RH provided python for development.

> May I ask why?

A great deal of the Red Hat management tools use that Python, so it's not something I advocate altering beyond the python packages provided by RHEL/CentOS/Scientific Linux.

Yes I can use virtualenv, but by the time I'm going that far, especially in the event of deploying 100's to 1000's of hosts, having a separate installation just isn't so difficult.