Python: Lazy Import Fix and IDLE Hardening
Core correctness fixes landed for lazy imports and reverse dictionary iteration, alongside a cluster of IDLE crash fixes. Performance work also advanced with a match-statement fast path and a proposed C parser for strptime.
Duration: PT2M32S
Episode overview
This episode is a short developer briefing from Python.
It explains recent repository work in plain language.
- Show: Python
- Published: 2026-09-27T13:07:22Z
- Audio duration: PT2M32S
Transcript excerpt
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Good morning, it's Sunday, September 27th, 2026.
The lead signal this week is core correctness — the import system and dictionary iteration both got fixes for cases where Python silently did the wrong thing.
First, lazy imports. Pull request 158092 fixes what quote lazy import A dot B as C unquote actually imports. Previously, reification imported only the top package and then read B off it as an attribute, so a shadowing attribute could answer instead of the real submodule. It also meant quote lazy import math dot pi…
Related, pull request 158255 fixes reverse dictionary iterators. Forward iterators already raised when keys changed mid-iteration, but reverse iterators only checked size. After a clear and refill to the same size, they could keep yielding new keys and the length hint could wrap around. They now raise dictionary…
Second theme: IDLE reliability. Three separate fixes landed. Pull request 153481 stops a crash when a file open in the editor is deleted externally — refocusing the window no longer lets a missing-file error escape. Pull request 135526 fixes truncated multi-line messages for name and attribute errors in IDLE's…
Third, performance. Pull request 144820 adds a…
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