Run this code with tracker node selected. This will create a roto node with selected tracker nodes  track information baked. So draw shape at any point and it will follow the tracked object..

This code will bake tracking information based on your tracker node. If your tracker node enabled only transform information then it will connect only the transform value. If your tracker enabled TRS then it will connect all the information automatically.

This code create default roto node while user selected other nodes or nothing is selected.

menu.py lines:

import trackRoto
n = nuke.toolbar('Nuke')
n.addCommand('Edit/trackRoto', 'trackRoto.trackRoto()', 'O')

I'm over riding nuke's default shortcut 'O'. This code create default roto node if no Tracker node selected or nothing selected. Used re function to get rid of Tracker node versions issue. So, No need to worry about what nuke version your using. This code will work across all the nuke version.