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A “frozen” dictionary for Python

(lwn.net)
191 points jwilk | 1 comments | 11 Dec 25 09:51 UTC | HN request time: 0.214s | source
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codethief ◴[11 Dec 25 11:17 UTC] No.46230017[source]▶
Next step: Auto-inferring the correct (most narrow) TypedDict type from a frozendict. (Think `const foo = { … } as const` in TypeScript.) I miss this TS feature in Python on the daily.
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mrweasel ◴[11 Dec 25 12:03 UTC] No.46230354[source]▶
What would that do exactly? Auto-generate a TypedDict class?

Bringing up TypedDict is sort of interesting, because it seems like a frozen dictionary could have been implemented by PEP 705, if typing.ReadOnly was enforced at runtime, and not just a hint to a static type checker.

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dmurray ◴[11 Dec 25 12:15 UTC] No.46230430[source]▶
Auto-generate a TypedDict type while type checking, while doing nothing at runtime.

I expect this is not a very big ask and the various typecheckers will have versions of this soon after release.

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1. codethief ◴[11 Dec 25 15:27 UTC] No.46232554[source]▶
After what release? Type checkers already support the various TypedDict PEPs, even those that haven't been accepted yet. Yet, none of them infers TypedDict types.