Python 2.7 was used in Poser 11.  Python org AND its python developers ended support for this release of python on 1 Jan 2020. This is the reason that later versions of Poser began to use Python 3.

Ken1171 has written many python scripts that work in Poser 13. He would be the most likely person to contact to request some of the python functions you most need for Poser 13 and later.