Python 3.13.1 Released November 2025 'link' -

Kavya’s closing slide read: “Python isn’t slow anymore. You just haven’t updated.”

- Full standard library support. interp.run() now behaves as predictably as threading . No more "RuntimeError: cannot call daemon thread" surprises. python 3.13.1 released november 2025

# November 2025 changed everything. # Let's see what November 2030 brings. import Kavya’s closing slide read: “Python isn’t slow anymore

She hit enter.

The no_gil build meant that reference counting had to be atomic. The 3.13.1 team had implemented a brilliant biased reference counting scheme with per-object locks, but it exposed a decade of sins. Libraries that relied on the GIL for thread safety—without a single threading.Lock in sight—now corrupted their own data structures with cheerful abandon. No more "RuntimeError: cannot call daemon thread" surprises

The Python Software Foundation archives still hold the release announcement for 3.13.1. Underneath the technical changelog, in a small gray font, is a note from the release manager—a woman named Priya Sharma, who Elena had hugged at PyCon US 2025.