PyROOT is the Python binding of the CERN ROOT library. Apparently, major changes have been introduced for the ROOT v6.22 release — see the Release Note and blog post, using modern technology such as cling and cppyy. It also adds the ability to build PyROOT for both Python 2 and 3 (see manual). A lot of old hacks for PyROOT might become obsolete at this point. But I believe the modernization of PyROOT is very much desired.