Proposal: Remove Python 3.10 support earlier than EOL

[lanctot]

Hi,

I propose we remove support for Python 3.10 early as it's causing multiple issues:

• We need to move to the new use of MutexLock because the old one is now deprecated, but the machines that need to compile the wheel for 3.10 are too old on MacOS (see Remove Python 3.10 support, update abseil version + change uses of MutexLock #1424 )
• We should move to nnx for our neural net uses, and its newest API requires Python 3.11. This is required for AlphaZero (Alpha zero refactor (testing and polishing) #1362 ) and several refactors of basic algorithms like DQN and Deep CFR (see DQN refactor #1419 , Deep cfr jax refactor #1408)

Before we do this we need to make sure that the most common use cases (i.e. Colab, Kaggle Game Arena) do not rely on Python 3.10. If not, we anticipate removing it in the next few weeks.

If this would cause issues for you please let us know ASAP.

[lanctot]

Just checked: Colab (both GPU and TPU kernels) both use Python 3.12, so the colab use case would not be affected.

[alexunderch]

The latest jax version requires numpy>=2.0 which was upgraded only since torch==2.4

Latest Stable PyTorch requires Python 3.10 or later. source

Jax's recent versions are supported from python3.11 with the next deprecation is in July 2026: source. This implies that the support for 3.10 was removed half a year ago.

[alexunderch]

For 3.10, the lastest I could get is

export OPEN_SPIEL_PYTHON_PYTORCH_DEPS="torch==2.9.1"
export OPEN_SPIEL_PYTHON_JAX_DEPS="jax==0.6.2 jaxlib==0.6.2 flax==0.10.7 dm-haiku==0.0.16 optax==0.2.6 chex==0.1.90 rlax==0.1.7 distrax==0.1.5"

current tests should pass for these requirements, however, no idea about the newest nnx modules. Let's see what we can get, before dropping 3.10

[alexunderch]

Replying to #1419 (comment), yes, it's completely ok to understand if I should make everything work for python3.10 as well, or not. For a while, I will keep on working on the current PR as they for >3.10.

@lanctot , to keep everything in one place, sorry replying in different place

[lanctot]

Actually I don't think we can drop Python 3.10 as OpenSpiel is used in kaggle-environments for the Kaggle Game Arena and its newest version (released just a few weeks ago) still supports >= 3.10:

https://pypi.org/project/kaggle-environments/1.25.7/

I will coordinate with them for a time that we can make those changes.

@alexunderch can you try those latest versions that work with 3.10 in the AlphaZero PR?

[alexunderch]

sure, will do so

[sriramsowmithri9807]

hey @lanctot checkout the pullrequest #1430

[alexunderch]

@sriramsowmithri9807 I think it's decided that it's not the first priority to remove the version 3.10 rn

[lanctot]

hey @lanctot checkout the pullrequest #1430

Thanks @sriramsowmithri9807 but see #1425 (comment), we will put this off to October or whenever kaggle-environments upgrades to >= 3.11.

I am in touch with them so I can coordinate, thanks anyway.

[sriramsowmithri9807]

Thanks @lanctot for the update happy to revisit after the ≥ 3.11 upgrade.

I’m aiming to contribute to DeepMind for GSoC 2026 and would appreciate any guidance on beginner-friendly issues to start with.