You can link the viewpoint to a mouse/keyboard tracker and apply a link operator to that:
Code:
import viz
viz.go()
gallery = viz.addChild('gallery.ive')
import viztracker
tracker = viztracker.KeyboardMouse6DOF()
link = viz.link(tracker,viz.MainView)
link.postEuler([180,0,0])
Does this do what you want?