Registering for publications and subscribing

You need to register for publications before you can publish on a certain topic. To do so, call zerosmq.register_publish("SOME_TOPIC"), replacing SOME_TOPIC by a more appropriate label.

Warning

Labels must be a single word!

If your label has spaces, replace them by underscores or delete them. In its present form, ZeROSMQ makes no effort whatsoever to ensure that topics have a single word, and ZeroMQ expects topics to have a single word, so it is your job to ensure it.

You also need to subscribe to a topic before you receive updates for it. To do so, call zerosmq.subscribe("SOME_TOPIC"), replacing SOME_TOPIC with the desired topic. The same warning applies regarding whitespace and single words.

Note: it is recommended to register for all publications first, then wait for a while, and then subscribe. This gives the master time to process all registrations. You can do so, for example, by calling import time and then calling time.sleep(1) between zerosmq.register_publish() calls and zerosmq.subscribe() calls (obviously, you must order them so that zerosmq.register_publish() calls appear first). This sleeps the node for one second and gives any other nodes time to announce their own publications.