R from EPEL has been updated to version 3.
We would like to run rpy2 but as of rpy2 version 2.3.x, it requires Python 2.7.
Red Hat Enterprise Linux 6 comes with Python 2.6.
So we need Python 2.7 so we can use rpy2 2.3 so we can use R 3.
The solution is to create a Python virtualenv containing Python 2.7 and install rpy2 in there. That way a user can log in and get Python 2.7 when they type python at the command line.