Well, if you were and are staying on Python 2.7, you are committing to anywhere from 6 (if you start now) to 10 (if you started day of 2.7.0 release) years of a frozen, non-evolving language. No new features, no improvements, nothing -- just the same language, for a decade.

If you can live with that, then by all means stick to 2.7 until your Red Hat support contract expires. If not, consider switching to 3.x.