gh-141510: Use frozendict in the _opcode_metadata

[vstinner]

Enhance py_metadata_generator.py to skip duplicates.

• Issue: PEP 814: Add built-in frozendict type #141510

[corona10]

We need agreement from the maintainer according to the SC recommendation.

[vstinner]

We need agreement from the maintainer according to the SC recommendation.

opcode has no maintainer according to https://devguide.python.org/core-team/experts/ and .github/CODEOWNERS.

I think that a review from 1 or 2 core devs should be enough here.

[vstinner]

cc @Fidget-Spinner

[Fidget-Spinner]

cc @Fidget-Spinner

Hmm I'm not too sure. Semantically making it frozen dict is correct. However, do people use this in the wild or modify it in-place? I know it's read by PyTorch for example, but I don't know if it's modified.

[vstinner]

I know it's read by PyTorch for example, but I don't know if it's modified.

PyTorch uses the C API, include <internal/pycore_opcode_metadata.h> with NEED_OPCODE_METADATA macro defined: https://github.com/search?q=repo%3Apytorch%2Fpytorch%20_opcode_metadata&type=code

This internal header file declares data as read-only. Example: const struct opcode_metadata _PyOpcode_opcode_metadata[267], notice the const in the type.

However, do people use this in the wild or modify it in-place?

It sounds weird to me to modify _opcode_metadata dictionaries. Why would someone do that? You can easily create your own copy if you really need changes.

[corona10]

It sounds weird to me to modify _opcode_metadata dictionaries. Why would someone do that? You can easily create your own copy if you really need changes.

I think that we need to sync with Cinder and PyTorch people at core team Discord.

[corona10]

lgtm

[vstinner]

Merged, thanks for the review.