Py Trees

Status

Devel	0.8.x	0.6.x	0.5.x

About

This is a python3 implementation of behaviour trees designed to facilitate the rapid development of medium sized decision making engines for use in fields like robotics. Brief feature list:

• Sequence, Selector, Parallel and Chooser composites
• Blackboards for data sharing
• Python generators for smarter ticking over the tree graph
• Python decorators for enabling meta behaviours
• Render trees to dot graphs or visualise with ascii graphs on stdout

Note: Official python2 support was dropped in the 0.6.x releases although it may 'just work'.

Installation

From ppa on Ubuntu/Bionic:

$ sudo apt install python3-py-trees

From pypi:

$ pip install py_trees

From the ROS2 ecosystem:

$ sudo apt install ros-<rosdistro>-py-trees

In a Python Virtual Environment:

$ git clone https://github.com/stonier/py_trees
$ cd py_trees
$ source ./virtualenv.bash

Build your own python3 deb:

$ git clone https://github.com/stonier/py_trees
$ cd py_trees
$ source ./virtualenv.bash
$ make deb

Demos and Tutorials

API, guides and demo instructions can be found in the sphinx generated documetnation on Read-The-Docs (devel, 0.8.x, 0.6.x)!

PyTrees in ROS

This repository is python-only, however additional modules & documentation are available for using py_trees with ROS that provide ROS-specific behaviours, logging, tools and visualisations in ROS.

	ROS2/Bouncy	ROS1/Melodic	ROS1/Kinetic
py_trees
py_trees-msgs	-
py_trees-ros	-
rqt_py_trees	-

Release Notes

Forthcoming

1.0.3 (2018-10-19)

• [visitors] winds of change visitor and logging demo

1.0.2 (2018-10-18)

• [console] fallbacks for unicode chars when (UTF-8) encoding cannot support them

1.0.1 (2018-10-18)

• [trees] don\'t use multiprocess on setup if not using timeouts

1.0.x (2019-01-18)

Breaking API

• [behaviour] setup() no longer returns a boolean, catch exceptions instead, #143.
• [behaviour] setup() no longer takes timeouts, responsibility moved to BehaviourTree, #148.
• [decorators] new-style decorators found in py_trees.decorators
• [decorators] new-style decorators stop their running child on completion (SUCCESS||FAILURE)
• [decorators] old-style decorators in py_trees.meta deprecated

New Features

• [blackboard] added a method for clearing the entire blackboard (useful for tests)
• [composites] raise TypeError when children\'s setup methods don\'t return a bool (common mistake)
• [composites] new parallel policies, SuccessOnAll, SuccessOnSelected
• [decorators] oneshot policies for activating on completion or successful completion only
• [meta] behaviours from functions can now automagically generate names

0.8.x (2018-10-18)

Breaking API

• Lower level namespace types no longer exist (PR117), e.g. py_trees.Status{.sourceCode} -> py_trees.common.Status{.sourceCode}
• Python2 support dropped

New Features

• [idioms] \'Pick Up Where You Left Off\'
• [idioms] \'OneShot\'

0.8.0 (2018-10-18)

• [infra] shortcuts to types in __init__.py removed (PR117)
• [bugfix] python3 rosdeps
• [idioms] pick_up_where_you_left_off added

0.7.5 (2018-10-10)

• [idioms] oneshot added
• [bugfix] properly set/reset parents when replacing/removing children in composites

0.7.0 (2018-09-27)

• [announce] python3 only support from this point forward
• [announce] now compatible for ros2 projects

0.6.5 (2018-09-19)

• [bugfix] pick up missing feedback messages in inverters
• [bugfix] eliminate costly/spammy blackboard variable check feedback message

0.6.4 (2018-09-19)

• [bugfix] replace awkward newlines with spaces in ascii trees

0.6.3 (2018-09-04)

• [bugfix] don\'t send the parellel\'s status to running children, invalidate them instead

0.6.2 (2018-08-31)

• [bugfix] oneshot now reacts to priority interrupts correctly

0.6.1 (2018-08-20)

• [bugfix] oneshot no longer permanently modifies the original class

0.6.0 (2018-05-15)

• [infra] python 2/3 compatibility

0.5.10 (2017-06-17)

• [meta] add children monkeypatching for composite imposters
• [blackboard] check for nested variables in WaitForBlackboard

0.5.9 (2017-03-25)

• [docs] bugfix image links and rewrite the motivation

0.5.8 (2017-03-19)

• [infra] setup.py tests_require, not test_require

0.5.7 (2017-03-01)

• [infra] update maintainer email

0.5.5 (2017-03-01)

• [docs] many minor doc updates
• [meta] bugfix so that imposter now ticks over composite children
• [trees] method for getting the tip of the tree
• [programs] py-trees-render program added

0.5.4 (2017-02-22)

• [infra] handle pypi/catkin conflicts with install_requires

0.5.2 (2017-02-22)

• [docs] disable colour when building
• [docs] sidebar headings
• [docs] dont require project installation

0.5.1 (2017-02-21)

• [infra] pypi package enabled

0.5.0 (2017-02-21)

• [ros] components moved to py_trees_ros
• [timeout] bugfix to ensure timeout decorator initialises properly
• [docs] rolled over with napolean style
• [docs] sphinx documentation updated
• [imposter] make sure tip() drills down into composites
• [demos] re-organised into modules

0.4.0 (2017-01-13)

• [trees] add pre/post handlers after setup, just in case setup fails
• [introspection] do parent lookups so you can crawl back up a tree
• [blackboard] permit init of subscriber2blackboard behaviours
• [blackboard] watchers
• [timers] better feedback messages
• [imposter] ensure stop() directly calls the composited behaviour

0.3.0 (2016-08-25)

• failure_is_running decorator (meta).

0.2.0 (2016-06-01)

• do terminate properly amongst relevant classes
• blackboxes
• chooser variant of selectors
• bugfix the decorators
• blackboard updates on change only
• improved dot graph creation
• many bugfixes to composites
• subscriber behaviours
• timer behaviours

0.1.2 (2015-11-16)

• one shot sequences
• abort() renamed more appropriately to stop()

0.1.1 (2015-10-10)

• lots of bugfixing stabilising py_trees for the spain field test
• complement decorator for behaviours
• dot tree views
• ascii tree and tick views
• use generators and visitors to more efficiently walk/introspect trees
• a first implementation of behaviour trees in python