ROS2 get the class of a given topic

edit

sorry! I meant from a ROS2 python node.

What do you mean for "class"?

the message type of a given topic through a python ros2 node.

It does not make sense. In a node you import (using Python) already at the beginning of the file the message type (or class if you prefer), that you want to subscribe/publish. If I understood, you want a node, which automatically detect a topic and then it tries to identify the message sent. It does not make sense such design, since you could expect anything from a string to a pose messagge.

It has no sense for you because you have assumed that I only want to send messages through a given topic. What I would like to know is if is there a function y Python like the cpp get_topic_names_and_types function.

My assumption is based on what you wrote in your post above and on the information you gave us.

Please, stop making noise if you cannot help me.

Hi lfb, As I mentioned before, you can run ros2 topic list through an terminal and get the type. I found an example on how to use the API you just mentioned in the following link

Let me know if this helps.