Python: Asyncio Cleanup and Free-Threading Safety
A cluster of asyncio fixes closes resource leaks and duplicate-callback bugs, while a separate line of work continues hardening free-threaded Python against use-after-free crashes in iterators and container types. IDLE also saw a multi-release consolidation of mouse wheel handling ahead of a bigger tree-widget rewrite.
Duration: PT2M45S
Episode overview
This episode is a short developer briefing from Python.
It explains recent repository work in plain language.
- Show: Python
- Published: 2026-09-06T13:06:15Z
- Audio duration: PT2M45S
Transcript excerpt
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Good morning. It's September 6th, and today's codebase activity centers on asyncio reliability and free-threading safety.
Start with asyncio. Several merged fixes address the same class of bug: transports and connections not cleaning up correctly on error or cancellation paths. Timofei Ivankov's fix in PR 156657 stops connection_lost from firing twice when resume_writing is called, and that same author's PR 157005 and 157004 restore a…
Second theme: free-threading correctness. Aarni Koskela's PR 156311 fixes a double-decref and use-after-free race in the plain iter() sequence fallback iterator, applying the same atomic-index pattern already used for list and tuple iterators. Separately, PR 157000 targets a similar race in xml.etree.ElementTree's…
Third, smaller theme: IDLE. Serhiy Storchaka's mouse wheel consolidation, PR 156974, moved wheel handling into a shared utility and was immediately backported to 3.14 and 3.13. He's since opened PR 157029, replacing IDLE's hand-drawn tree widget with a ttk Treeview to fix HiDPI clipping — a bigger structural change…
Also notable: a compiler crash on deeply nested comprehensions, fixed in PR 156957 and already backported, and a json…
That's…
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