Py Trees

[About][Status][Installation][Demos & Tutorials][PyTrees-Ros Ecosystem]

About

PyTrees is a python 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

Status

	Devel	1.2.x	0.6.x	0.5.x
Sources
Compatibility
Continuous Integration
Documentation

Installation

From ppa on Ubuntu/Bionic:

$ sudo apt install python3-py-trees

From pypi:

$ pip install py_trees

In a Python Virtual Environment:

$ git clone https://github.com/splintered-reality/py_trees
$ cd py_trees
$ source ./virtualenv.bash

Build your own python3 deb:

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

From the ROS2 ecosystem:

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

Demos and Tutorials

PyTrees-ROS Ecosystem

See the py_trees_ros README for the latest information on pytrees packages in the ROS ecosystem and their status.

Release Notes

1.2.1 (2019-05-21)

• [decorators] StatusToBlackboard reflects the status of it\'s child to the blackboard, #195
• [decorators] EternalGuard decorator that continuously guards a subtree (c.f. Unreal conditions), #195
• [idioms] eternal_guard counterpart to the decorator whose conditions are behaviours, #195

1.2.x (2019-04-28)

Breaking API

• [trees] removes the curious looking and unused destroy() method, #193
• [display] ascii_tree -> ascii_tree/unicode_tree(), no longer subverts the choice depending on your stdout, #192
• [display] dot_graph -> dot_tree for consistency with the text tree methods, #192

New Features

• [behaviour] shutdown() method to compliment setup(), #193
• [decorators] StatusToBlackboard reflects the status of it\'s child to the blackboard, #195
• [decorators] EternalGuard decorator that continuously guards a subtree (c.f. Unreal conditions), #195
• [display] xhtml_tree provides an xhtml compatible equivalent to the ascii_tree representation, #192
• [idioms] eternal_guard counterpart to the decorator whose conditions are behaviours, #195
• [trees] walks the tree calling shutdown() on each node in it\'s own shutdown() method, #193
• [visitors] get a finalise() method called immediately prior to post tick handlers, #191

1.1.0 (2019-03-19)

Breaking API

• [display] print_ascii_tree -> ascii_tree, #178.
• [display] generate_pydot_graph -> dot_graph, #178.
• [trees] tick_tock(sleep_ms, ..) -> tick_tock(period_ms, ...), #182.

New Features

• [trees] add missing add_visitor() method
• [trees] flexible setup() for children via kwargs
• [trees] convenience method for ascii tree debugging
• [display] highlight the tip in ascii tree snapshots

Bugfixes

• [trees] threaded timers for setup (avoids multiprocessing problems)
• [behaviour|composites] bugfix tip behaviour, add tests
• [display] correct first indent when non-zero in ascii_tree
• [display] apply same formatting to root as children in ascii_tree

1.0.7 (2019-xx-yy)

• [display] optional arguments for generate_pydot_graph

1.0.6 (2019-03-06)

• [decorators] fix missing root feedback message in ascii graphs

1.0.5 (2019-02-28)

• [decorators] fix timeout bug that doesn\'t respect a child\'s last tick

1.0.4 (2019-02-26)

• [display] drop spline curves, it\'s buggy with graphviz 2.38

1.0.3 (2019-02-13)

• [visitors] winds of change visitor and logging demo

1.0.2 (2019-02-13)

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

1.0.1 (2018-02-12)

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

1.0.0 (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