Select Point/Prim

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=22021&highlight=&sid=b3d35d7dbeb7e1e8c729ed199ccf1723

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&p=102109&sid=79ca6a0899568ba575f4f09b0ced4282

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&p=122000&sid=84a64815ec345d3ec0a44aac2bdda8dd

Basic Code to get selected prim string

import toolutils

viewer = toolutils.sceneViewer()

geo = viewer.selectGeometry()

prims = geo.mergedSelectionString()

If you want get list of Prims

listPrim = hou.selectedNodes()[0].geometry().globPrims(prims)

Just list of Prim numbers

listPrimNum = []

for i in listPrim:

listPrimNum.append(i.number())