Changelog¶

Notable changes to ProbingEnvironments. The format follows Keep a Changelog, and versions follow semantic versioning.

[Unreleased]¶

Characterization pins (tests/characterization/) record how every environment behaves today, through the API users and Ajax rely on. They keep the 0.7 refactor honest: a restructuring must leave them unchanged, and each deliberate behaviour change shows up as a pin difference with its own upgrade note here. No change to the package.

A minor release, because these changes break code written for 0.5.1:

gymnax 1.0 or newer is required. 0.5.1 required gymnax 0.0.9, so it could not be installed next to gymnax 1.x, and its environments failed on their first step under gymnax 1.0. Upgrade gymnax to >=1.0.
The gymnax environments follow the gymnax 1.0 API.
env.step returns six values, (obs, state, reward, terminated, truncated, info), instead of five. Unpack the extra value, and bootstrap your value targets at truncated steps: a time limit is no longer folded into done.
Environments implement is_terminated(state, params) instead of is_terminal. Rename it in your subclasses.
get_obs takes (state, params=None, key=None). Add the two optional arguments to your overrides.
The gymnax TwoChoiceMDP never terminates. Its episodes now end only at the time limit, reported as truncated, so an agent should bootstrap there.
pytest is no longer installed with this package. It moved to the development dependencies; add it to your own if you relied on it.
The Gymnasium environments draw from their own generator. reset(seed=s) seeds env.np_random, as Gymnasium specifies, instead of reseeding numpy's global generator, and a later reset() continues that stream. Seeded start observations no longer match 0.5.1's, where only the first one depended on the seed. If your code relied on reset seeding np.random, seed it yourself.

The sb3 extra: pip install "probing-environments[sb3]" installs Stable-Baselines3 for the premade adaptor.
A documentation site, versioned per release: https://yannberthelot.github.io/ProbingEnvironments/

jax, flax and numpy are declared as dependencies. The package imports them directly; before, they only arrived through gymnax.
six is declared: gymnax 1.0.1 imports it without declaring it, so a fresh install could not import the package.
Python 3.11 to 3.14 is supported; gymnax 1.0.1 supports Python below 3.15.
The package is built with hatchling and versioned from git tags. Release tags are now named vX.Y.Z; earlier ones had no v.

probing_environments.adaptors.ajax warns on import and will be removed in 0.7.0. Ajax ships its own probe adaptor in its test suite.

A seeded run through the SB3 adaptor is reproducible. The Gymnasium environments reseeded numpy's global generator from OS entropy on every automatic reset, so each run differed and the README's PPO example failed about once in 50 runs.