Attention: Answers.ros.org is deprecated as of August the 11th, 2023. Please visit robotics.stackexchange.com to ask a new question. This site will remain online in read-only mode during the transition and into the foreseeable future. Selected questions and answers have been migrated, and redirects have been put in place to direct users to the corresponding questions on Robotics Stack Exchange. Additional details are available here.

rospy publisher and subscriber in the same node, filter out "own" messages

publisher+subscriber

asked 2016-04-11 10:24:48 -0600

peci1

1366 ●27 ●69 ●60

Hey ROS folks

I have a node in Python, in which I subscribe to a topic, and I also want to simultaneously publish on it. And this node is not the only one doing that. In the subscriber, I want to filter out messages which are generated by my node.

Is there any API/package to do that?

In C++, I can imagine publishing/subscribing shared pointers, remembering a few last published messages, and comparing the memory address of the received message with the remembered addresses.

In Python, this is obviously not possible. Or is it?

If the messages have Header fields in them, it might be possible to filter them based on timestamp. Unfortunately, my messages do not have a header, and I can't alter the message definition.

edit retag flag offensive close merge delete

add a comment

1 Answer

Sort by » oldest newest most voted

answered 2016-04-11 10:52:46 -0600

lucasw

8729 ●137 ●239 ●256 https://github.com/lucasw

updated 2016-04-11 11:07:04 -0600

How about looking at the _connection_header callerid [Publishers and Subscribers] shown in ( http://wiki.ros.org/rospy/Overview/Pu... ) ?

It says 'We do not recommend using callerid information beyond debugging purposes, as it can lead to brittle code in an anonymous publish/subscribe architecture.'- but it seems like you could reliably get the name of your own node- I did a check and rospy.get_name() and callerid do match up when publishing and subscribing to the same topic in the same node.

edit flag offensive delete link

Comments

Thanks! Exactly what I was looking for.

peci1 ( 2016-04-11 11:15:32 -0600 )edit

add a comment

Question Tools

2 followers

Stats

Asked: 2016-04-11 10:24:48 -0600

Seen: 559 times

Last updated: Apr 11 '16

rospy publisher and subscriber in the same node, filter out "own" messages edit

1 Answer

Comments

Question Tools

Stats

Related questions

rospy publisher and subscriber in the same node, filter out "own" messages