should I be using python2 or python3?

I am using osops-tools-monitoring/monitoring-for-openstack to monitor an older openstack install (Liberty). I am running it in a docker container. I recently rebuilt the container in order to update some checks and found that the code had moved from github to opendev.

The commit messages on opendev seem to imply that python3 should work, but there are some basic problems still (e.g importing StringIO instead of io.StringIO), so I have to believe that I need to use python2.7 still. But that throws errors trying to import more_itertools/more.

Are there plans to get this working python3 soon? I would be willing to help, but to be honest, I do not know how big a job this is.