Red Hat added python3 to RHEL 7.7, but at least for now has declined to turn on the python3 subpackage in the libselinux spec file.
https://bugzilla.redhat.com/show_bug.cgi?id=1719978
I have attempted to to extract the python3 subpackage into it's own spec file. It seems to work as best I can tell. I have submitted it for review as an EPEL7-only package.
https://bugzilla.redhat.com/show_bug.cgi?id=1754039
I would love feedback on this if anyone has time to take a look.
python-devel@lists.fedoraproject.org