Python 3.15.0 was added to the actions/python-versions repository, allowing developers to use "3.15" in GitHub Actions testing matrices following the stable Python 3.15.0 release. Simon Willison shared the link after tracking the update.
# Python 3.15.0 added to actions/python-versions
Source: [https://simonwillison.net/2026/Oct/10/python-actions/](https://simonwillison.net/2026/Oct/10/python-actions/)
10th October 2026 \- Link Blog
**[Python 3\.15\.0 added to actions/python\-versions](https://github.com/actions/python-versions/commit/49858b91c92d27403416ee43117032e91d00ce24)**\. Bit of a niche link, but I've been waiting for this for a couple of days \- I even[told ChatGPT](https://chatgpt.com/share/6acad42a-2868-83e8-9a16-736f9def2b45)to check for it:
> `Clone https://github\.com/actions/python\-versions and git pull once an hour until they add the stable 3\.15 \- then tell me about it`
Now that this has landed, you can add`"3\.15"`to a GitHub Actions testing matrix to run tests against the[new Python 3\.15\.0 release](https://www.python.org/downloads/release/python-3150/)\.
Posted[10th October 2026](https://simonwillison.net/2026/Oct/10/)at 11:58 pm
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This is a**link post**by Simon Willison, posted on[10th October 2026](https://simonwillison.net/2026/Oct/10/)\.
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Python 3.15 is released, featuring lazy imports via a new `lazy` keyword, the Tachyon statistical sampling profiler, sentinel types, and more, alongside updated Astral tools Ruff, uv, and ty.
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