# The meaning of manually written "multiple\_broadcaster.py" **URL:** \ **Category:** TF ROS 101\ **Created:** [October 11, 2022, 9:20am UTC](https://get-help.theconstruct.ai/t/the-meaning-of-manually-written-multiple-broadcaster-py/19838 "2022-10-11T09:20:10Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![MeineLiebeAxt](https://get-help.theconstruct.ai/letter_avatar_proxy/v4/letter/m/45deac/32.png) [@MeineLiebeAxt](https://get-help.theconstruct.ai/u/MeineLiebeAxt)\ **Post date:** [October 11, 2022, 9:20am UTC](https://get-help.theconstruct.ai/t/the-meaning-of-manually-written-multiple-broadcaster-py/19838/1 "2022-10-11T09:20:10Z")
Hi, I am doing “3 Publisch & Subscribe to TF data” of “TF” course. In this case we are learning how to write a py-file to broadcast/publish TF data. But I find that even though without this manually written py-file, we can still see turtle1 and turtle2 in rqt\_tf\_tree and rviz. If we add “coke\_can” in name\_list in this py-file, rqt\_tf\_tree will add “coke\_can” as well. But why “turtle1” and “turtle2” always show themselves? Where has this defined? Even though I set the name\_list in “multiple\_broadcaster.py” just as [“coke\_can”], “turtle1” and “turtle2” remain. As a result, what is the meaning of this manually written “multiple\_broadcaster.py”? Just add ‘‘other’’ objects to present? The manually written “multiple\_broadcaster.py” is here: ```auto #! /usr/bin/env python import rospy import time import tf from turtle_tf_3d.get_model_gazebo_pose import GazeboModel class MultiTfBroadcast(object): ``` ``` def __init__ (self, robot_name_list, loop_rate=5.0): self._robot_name_list = robot_name_list self._gazebo_model_object = GazeboModel(self._robot_name_list) # hz self._rate = rospy.Rate(loop_rate) # We start the Tf broadcaster self._broad_caster_tf = tf.TransformBroadcaster() # Leave enough time to be sure the Gazebo Model logs have finished time.sleep(1) rospy.loginfo("Ready..Starting to Publish TF data now...") def handle_turtle_pose(self, pose_msg, robot_name, reference_frame_data="/world"): self._broad_caster_tf.sendTransform((pose_msg.position.x, pose_msg.position.y, pose_msg.position.z), (pose_msg.orientation.x, pose_msg.orientation.y, pose_msg.orientation.z, pose_msg.orientation.w), rospy.Time.now(), robot_name, reference_frame_data) def start_loop(self): while not rospy.is_shutdown(): for robot_name in self._robot_name_list: pose_now = self._gazebo_model_object.get_model_pose(robot_name) if not pose_now: robot_name_msg = "The " + \ str(robot_name) + \ "'s Pose is not yet available...Please try again later" rospy.loginfo(robot_name_msg) else: self.handle_turtle_pose(pose_now, robot_name) self._rate.sleep() ``` def main(): ``` rospy.init_node('publisher_of_tf_node', anonymous=True) multi_tf_broadcast_obj = MultiTfBroadcast( robot_name_list=["turtle1", "turtle2", "coke_can"]) try: multi_tf_broadcast_obj.start_loop() except rospy.ROSInterruptException: pass ``` if **name** == ‘ **main** ’: main() ---
**Author:** ![rzegers](https://get-help.theconstruct.ai/user_avatar/get-help.theconstruct.ai/rzegers/32/7010_2.png) [@rzegers](https://get-help.theconstruct.ai/u/rzegers)\ **Post date:** [October 12, 2022, 8:30am UTC](https://get-help.theconstruct.ai/t/the-meaning-of-manually-written-multiple-broadcaster-py/19838/2 "2022-10-12T08:30:32Z")
Hello @MeineLiebeAxt, as I understand from you post you are executing the multiple\_broadcaster.py script after having modified this line here: ```auto multi_tf_broadcast_obj = MultiTfBroadcast( robot_name_list=["turtle1", "turtle2"]) ``` into this: ```auto multi_tf_broadcast_obj = MultiTfBroadcast( robot_name_list=["coke_can"]) ``` and you are wondering why in the new version of your multiple\_broadcaster.py file the TF’s for turtle1 and turtle2 are also being published. Did I understand your question correctly? The answer is they should not be published. So something else must be causing this issue. To start, please confirm a few things: - You have saved your new `multiple_broadcaster.py` script and the line above is like so: ```auto multi_tf_broadcast_obj = MultiTfBroadcast( robot_name_list=["coke_can"]) ``` - You have stopped all ROS nodes running in every Webshell before you run you new code. To do so switch to every Webshell and press Ctrl + C. - Confirm that when you execute the script you see these lines printed out to the console: ```auto user:~/catkin_ws/src/tf_exercises_pkg$ rosrun tf_exercises_pkg multiple_broadcaster.py [INFO] [1665562839.223504, 0.000000]: Retrieveing Model indexes [INFO] [1665562839.256574, 481.781000]: Final robots_index_dict = {'coke_can': 1} [INFO] [1665562840.266317, 482.797000]: Ready..Starting to Publish TF data now... ``` The second INFO log shows the name of the objects who’s TF’s will be broadcasted in lines above it is just `coke_can`. In that case you should only see the TF for `coke_can` being published. Hope this helps, Roberto ---
**Author:** ![bayodesegun](https://get-help.theconstruct.ai/user_avatar/get-help.theconstruct.ai/bayodesegun/32/6966_2.png) [@bayodesegun](https://get-help.theconstruct.ai/u/bayodesegun)\ **Post date:** [October 17, 2022, 7:00am UTC](https://get-help.theconstruct.ai/t/the-meaning-of-manually-written-multiple-broadcaster-py/19838/3 "2022-10-17T07:00:45Z")
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