To operate on a push button object and based on your requirement, you can use any of these functions
click
enterstring - Generate keyboard event as if user key in
mouseleftclick - Generate mouse left click event
mousemove - Simulate mouse move to the specified co-ordinates
mouserightclick - Generate mouse right click event
stateenabled - Checks whether the push button is in enabled state
verifypushbutton - Verify whether the object is a push button
Linux Desktop Testing Project