py_trees_parser

erichlf · 2025-02-05T16:07:03.442Z

If you are interested in Behavior Trees, but you don’t want to use BehaviorTree.CPP (Davide Faconti’s amazing work), because you want to use python, but you prefer to build your trees as a config; well then, I have a treat for you. Introducing py_trees_parser; an xml parser for py_trees and [py_trees_ros(GitHub - splintered-reality/py_trees_ros: ROS extensions and implementations for py_trees).

The idea is that you can configure your behavior tree from an xml file and therefore you can easily change the layout of your behavior tree purely through a config. Eventually, I would like to add a GUI, so that everything can be built via connecting boxes and filling in the necessary fields. Please drop in and check it out and feel free to add to the code and discussion.

dy314 · 2025-02-06T20:45:50.710Z

Hi,
that looks interesting. I am also working a lot with py_trees and currently working on a solution define the BTs in yaml-format for py_trees, to change and load them during runtime.
I will definitely try your xml-parser and give you feedback.

I do have one question in advance.
Can you parser also handle custom behaviors with parameters?

Thank you.

Best regards,
Daniel

erichlf · 2025-02-07T08:36:09.201Z

Absolutely. it can even handle python code as parameters. It just requires that the behaviors use the fully qualified name and that the python code also use fully qualified names. That is the only way for it to know what you are talking about.

An example might look like:

<py_trees.composites.Sequence name="MySequence">
    <my_behaviors.behaviors.Foo name="foo" param1="bar" param2="$(my_behaviors.foo())" />
</py_trees.composites.Sequence>