Release Notes#

v0.27.1#

Released on 2023-01-20 - GitHub - PyPI

Release Notes

Bugs fixed

New features/improvements

  • Improve LunarLander-v2 step performance by >1.5x by @PaulMest in #235
  • Added vector env support to StepAPICompatibility wrapper by @nidhishs in #238
  • Allow sequence to accept stacked np arrays if the feature space is Box by @jjshoots in #241
  • Improve the warning when an error is raised from a plugin by @pseudo-rnd-thoughts in #225
  • Add changelog (release notes) to the website by @mgoulao in #257
  • Implement RecordVideoV0 by @younik in #246
  • Add explicit error messages when unflatten discrete and multidiscrete fail by @PierreMardon in #267

Documentation updates

Thanks to the new contributors to Gymnasium, if you want to get involved, join our discord server. Linked in the readme.

Full Changelog: v0.27.0...v0.27.1

v0.27.0#

Released on 2022-12-12 - GitHub - PyPI

Release Notes

Gymnasium 0.27.0 is our first major release of Gymnasium. It has several significant new features, and numerous small bug fixes and code quality improvements as we work through our backlog. There should be no breaking changes beyond dropping Python 3.6 support and remove the mujoco Viewer class in favor of a MujocoRendering class. You should be able to upgrade your code that's using Gymnasium 0.26.x to 0.27.0 with little-to-no-effort.

Like always, our development roadmap is publicly available here so you can follow our future plans. The only large breaking changes that are still planned are switching selected environments to use hardware accelerated physics engines and our long standing plans for overhauling the vector API and built-in wrappers.

This release notably includes an entirely new part of the library: gymnasium.experimental. We are adding new features, wrappers and functional environment API discussed below for users to test and try out to find bugs and provide feedback.

New Wrappers

These new wrappers, accessible in gymnasium.experimental.wrappers, see the full list in https://gymnasium.farama.org/main/api/experimental/ are aimed to replace the wrappers in gymnasium v0.30.0 and contain several improvements

  • (Work in progress) Support arbitrarily complex observation / action spaces. As RL has advanced, action and observation spaces are becoming more complex and the current wrappers were not implemented with this mind.
  • Support for Jax-based environments. With hardware accelerated environments, i.e. Brax, written in Jax and similar PyTorch based programs, NumPy is not the only game in town anymore for writing environments. Therefore, these upgrades will use Jumpy, a project developed by Farama Foundation to provide automatic compatibility for NumPy, Jax and in the future PyTorch data for a large subset of the NumPy functions.
  • More wrappers. Projects like Supersuit aimed to bring more wrappers for RL, however, many users were not aware of the wrappers, so we plan to move the wrappers into Gymnasium. If we are missing common wrappers from the list provided above, please create an issue and we would be interested in adding it.
  • Versioning. Like environments, the implementation details of wrappers can cause changes in agent performance. Therefore, we propose adding version numbers to all wrappers, i.e., LambaActionV0. We don't expect these version numbers to change regularly and will act similarly to environment version numbers. This should ensure that all users know when significant changes could affect your agent's performance for environments and wrappers. Additionally, we hope that this will improve reproducibility of RL in the future, which is critical for academia.
  • In v28, we aim to rewrite the VectorEnv to not inherit from Env, as a result new vectorized versions of the wrappers will be provided.

Core developers: @gianlucadecola, @RedTachyon, @pseudo-rnd-thoughts

Functional API

The Env class provides a very generic structure for environments to be written in allowing high flexibility in the program structure. However, this limits the ability to efficiently vectorize environments, compartmentalize the environment code, etc. Therefore, the gymnasium.experimental.FuncEnv provides a much more strict structure for environment implementation with stateless functions, for every stage of the environment implementation. This class does not inherit from Env and requires a translation / compatibility class for doing this. We already provide a FuncJaxEnv for converting jax-based FuncEnv to Env. We hope this will help improve the readability of environment implementations along with potential speed-ups for users that vectorize their code.

This API is very experimental so open to changes in the future. We are interested in feedback from users who try to use the API which we believe will be in particular interest to users exploring RL planning, model-based RL and modifying environment functions like the rewards.

Core developers: @RedTachyon, @pseudo-rnd-thoughts, @balisujohn

Other Major changes

  • Refactor Mujoco Rendering mechanisms to use a separate thread for OpenGL. Remove Viewer in favor of MujocoRenderer which offscreen, human and other render mode can use by @rodrigodelazcano in #112
  • Add deprecation warning to gym.make(..., apply_env_compatibility=True) in favour of gym.make("GymV22Environment", env_id="...") by @pseudo-rnd-thoughts in #125
  • Add gymnasium.pprint_registry() for pretty printing the gymnasium registry by @kad99kev in #124
  • Changes discrete dtype to np.int64 such that samples are np.int64 not python ints. by @pseudo-rnd-thoughts in #141
  • Add migration guide for OpenAI Gym v21 to v26 by @pseudo-rnd-thoughts in #72
  • Add complete type hinting of core.py for Env, Wrapper and more by @pseudo-rnd-thoughts in #39
  • Add complete type hinting for all spaces in gymnasium.spaces by @pseudo-rnd-thoughts in #37
  • Make window in play() resizable by @Markus28 in #190
  • Add REINFORCE implementation tutorial by @siddarth-c in #155

Bug fixes and documentation changes

Behind-the-scenes changes

v0.26.3#

Released on 2022-10-24 - GitHub - PyPI

Release Notes

Note: ale-py (atari) has not updated to Gymnasium yet. Therefore pip install gymnasium[atari] will fail, this will be fixed in v0.27. In the meantime, use pip install shimmy[atari] for the fix.

Bug Fixes

  • Added Gym-Gymnasium compatibility converter to allow users to use Gym environments in Gymnasium by @RedTachyon in #61
  • Modify metadata in the HumanRendering and RenderCollection wrappers to have the correct metadata by @RedTachyon in #35
  • Simplified EpisodeStatisticsRecorder wrapper by @DavidSlayback in #31
  • Fix integer overflow in MultiDiscrete.flatten() by @olipinski in #55
  • Re-add the ability to specify the XML file for Mujoco environments by @Kallinteris-Andreas in #70

Documentation change

Full Changelog: v0.26.2...v0.26.3

Thank you for the new contributors

v0.26.2: 0.26.2 #

Released on 2022-10-05 - GitHub - PyPI

This Release is an upstreamed version of Gym v26.2

Bugs Fixes

  • As reset now returns (obs, info) then in the vector environments, this caused the final step's info to be overwritten. Now, the final observation and info are contained within the info as "final_observation" and "final_info" @pseudo-rnd-thoughts
  • Adds warnings when trying to render without specifying the render_mode @younik
  • Updates Atari Preprocessing such that the wrapper can be pickled @vermouth1992
  • Github CI was hardened to such that the CI just has read permissions @sashashura
  • Clarify and fix typo in GraphInstance @ekalosak

v0.26.1: 0.26.1#

Released on 2022-09-16 - GitHub - PyPI

This Release is an upstreamed version of Gym v26.1

In addition, the gym docs repo has been merged in with the new website https://gymnasium.farama.org/

v0.26.0: Initial Release#

Released on 2022-09-13 - GitHub - PyPI

This is the first release of Gymnasium, a maintained fork of OpenAI Gym

This release is identical to the Gym v0.26.0 except for the project name (Gymnasium) and Code of Conduct

Read #12 for the roadmap of changes

Gym Release Notes#