The team is effectively saying: "We'll push major features, but we'll clean up fast."
docs.python.org/3.13/whatsnew/changelog.html Download: python.org/downloads/release/python-3131/ python 3.13.1 released today
3.13.1 fixes a subtle reference-counting race condition in weakref.finalize and a deadlock involving threading.Condition in free-threaded mode. These were hard to reproduce but real — several scientific computing early adopters reported them. The team is effectively saying: "We'll push major
Questions? Spotted a bug in 3.13.1 already? Drop a comment or ping me on Mastodon. And yes — I'll update this post if any critical CVEs emerge in the next 72 hours. Spotted a bug in 3
3.13.1 arrived just after 3.13.0, compared to the typical 90–120 days for past .1 releases. Why? Because 3.13.0 shipped with more experimental flags ( --disable-gil , --enable-experimental-jit ) than any release in a decade. Each flag is its own parallel universe of bugs.
The free-threaded future is coming. The JIT is coming. But today, we got a quieter gift: a Python that crashes less, pastes correctly, and respects your terminal.
Let me cut through the noise and tell you what actually matters. Python 3.13.1 is a bugfix release — the first in the 3.13 series. If you're running 3.13.0 (released October 7, 2024), you'll want this update. If you're still on 3.12 or earlier, this isn't your cue to upgrade just yet, but it's worth knowing what's coming.