Hi Mark,
I had the same problem some month ago. I started with the example from Zacobria but it was implemented with Python 2.7 and I needed Python 3.
After some Research I found a very cool and usefull API here in the UR Forum. This API uses all communication ports, also the RTDE. It is implemented with Python 3 and the API is powerful and easy to understand. You can use it to get all informations from the robot also the actual position.
You can find it here:
https://forum.universal-robots.com/t/python-3-library-to-communicate-with-robot/461
That might help you, too.
Regards,
Flo