Does the following work for you?
Code:
import viz
import vizact
viz.go()
viz.add('dojo.osgb')
ball = viz.addChild('beachball.osgb',pos=[0,1,4])
moveUp = vizact.move(0,1,0,1)
moveDown = vizact.move(0,-1,0,1)
vizact.onkeydown('1',ball.addAction,moveUp)
vizact.onkeydown('2',ball.addAction,moveDown)