Pose_now is being calculated twice

Course Support TF ROS 101
1

I have a doubt in the code from “multiple_broadcatser.py” from the chapter "Publish & Subscribe to TF data"

code snippet :

def publisher_of_tf():
    
    rospy.init_node('publisher_of_tf_node', anonymous=True)
    robot_name_list = ["turtle1","turtle2"]
    gazebo_model_object = GazeboModel(robot_name_list)
    
    
    for robot_name in robot_name_list:
        pose_now = gazebo_model_object.get_model_pose(robot_name)
    
    # Leave enough time to be sure the Gazebo Model logs have finished
    time.sleep(1)
    rospy.loginfo("Ready..Starting to Publish TF data now...")
    
    rate = rospy.Rate(5) # 5hz
    while not rospy.is_shutdown():
        for robot_name in robot_name_list:
            pose_now = gazebo_model_object.get_model_pose(robot_name)
            if not pose_now:
                print "The " + str(robot_name) + "'s Pose is not yet available...Please try again later"
            else:
                handle_turtle_pose(pose_now, robot_name)
        rate.sleep()

This particular part of the code where pose_now is being generated, is being calculated at two different points in the program, while I understand that the 2nd time (inside the while loop) its being sent to handle_turtle_pose I don’t understand why it is being used before time.sleep(1).

I tried commenting the 1st instance of pose_now and the code worked just fine, so I’m not really sure about its purpose.

TIA.

2

Hello @textzip,

Yes, you are right. It makes no sense to have the code being executed twice, so this is an error in the code provided. I will fix it as soon as possible.

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