Psse32 works with python 2.3, Psse33 and PSSe34 works with python 2.7. When py code is compiled into pyc code, it becomes PSSe version dependent. If you run the source py code, it should run in any Psse version.
From PSSe33 Release Note:
"Starting with release 33.4.0, a new command line switch has been supplied to allow you to run any
of several versions of Python with PSS®E, including the native interpreter for 2.7, the version that we
supply a rebuilt copy of. Through some internal conversions that we have developed, most of the original
problems have been avoided. If you specify no command line switch then you will still get the rebuilt
interpreter. The shortcut in the Start Menu will specify -pyver 27."