$ sudo apt-get install ros-indigo-executive-smach

$ git clone http://wiki.ros.org/smach/Tutorials

#!/usr/bin/env pythonimport roslib; roslib.load_manifest('smach_sample_node')
import rospy
import smach
import smach_ros
import time
# define state Foo       # define state Bar
class Open(smach.State):def __init__(self):smach.State.__init__(self, outcomes=['closed'])def execute(self, userdata):rospy.loginfo('Opened')time.sleep(2)rospy.loginfo('Closeing')return 'closed'    #define state close light
class Close(smach.State):def __init__(self):smach.State.__init__(self, outcomes=['opened'])def execute(self, userdata):rospy.loginfo('Closed')time.sleep(2)rospy.loginfo('Closing')return 'opened'

# main
def main():rospy.init_node('smach_example_state_machine')# Create a SMACH state machinesm_light = smach.StateMachine(outcomes=['stop', 'succee'])# Open the container
    with sm_light:# Add states to the containersmach.StateMachine.add('OPEN', Open(), transitions={'closed':'CLOSE'})smach.StateMachine.add('CLOSE', Close(), transitions={'opened':'OPEN'})# Execute SMACH plansis = smach_ros.IntrospectionServer('sm_light', sm_light, '/SM_ROOT')sis.start()# Execute SMACH planoutcome = sm_light.execute()# Wait for ctrl-c to stop the application
    rospy.spin()sis.stop()if __name__ == '__main__':main()

[INFO] [WallTime: 1453689512.106141] Closed
[INFO] [WallTime: 1453689514.108995] Closing
[INFO] [WallTime: 1453689514.109447] State machine transitioning 'CLOSE':'opened'-->'OPEN'
[INFO] [WallTime: 1453689514.109942] Opened
[INFO] [WallTime: 1453689514.420038] Closeing
[INFO] [WallTime: 1453689514.420271] State machine transitioning 'OPEN':'closed'-->'CLOSE'