RHEL 7 - Running Python 2 and Python 3 on the same system

I have a need to run both Python 2 and Python 3 on the same system.

What's the best way to run both Python 2 and 3 on the same system.

I don't want to compile anything manually so I'm guessing the Software Collections is where I'll be focusing my efforts.

Is it possible to integrate using SCL in systemd startup scripts for certain applications?

I'd be keen to hear of others experiences.