3 """ A dummy ROS node """     4 from __future__ 
import absolute_import
    20 if __name__ == 
'__main__':
    22         args = rospy.myargv(argv=sys.argv)
    23         node_name = args[1] 
if len(args) > 1 
else 'string_pub_node'    25         rospy.init_node(node_name)
    26         rospy.loginfo(
'String Pub node started. [' + rospy.get_name() + 
']')
    28         topic_name = rospy.get_param(
"~topic_name", 
"")
    29         print 'Parameter {0!s} has value {1!s}'.format(rospy.resolve_name(
'~topic_name'), topic_name)
    31             print "{0} parameter not found".format(rospy.resolve_name(
'~topic_name'))
    33         test_message = rospy.get_param(
"~test_message", 
"")
    34         print 'Parameter {0!s} has value {1!s}'.format(rospy.resolve_name(
'~test_message'), test_message)
    35         if test_message == 
"":
    36             print "{0} parameter not found".format(rospy.resolve_name(
'~test_message'))
    39         sub = rospy.Subscriber(topic_name, std_msgs.msg.String, topic_callback)
    43     except rospy.ROSInterruptException:
 
def topic_callback(self, data)