Migrate from __dataclass_transform__ to typing.dataclass_transform

[multimeric]

As of June 2022, PEP 681 has been accepted. Therefore, it would be good if Pydantic could migrate from __dataclass_transform__ (which was only ever a temporary measure) to typing.dataclass_transform, which would satisfy the PEP specification.

This would allow type checkers that support PEP 681 but not the intermediate measure to appropriately type check and autocomplete pydantic models.

[samuelcolvin]

But which versions of python is it available in? Is it available in typing-extensions? If so, is it recognized by all applicable type checkers?

What do well do about mypy where we have the dedicated extension?

[hmc-cs-mdrissi]

3.11 for python version. It is available in typing extensions. It is supported by pyright/pyre, while it is a no-op for the other type checkers. It won’t help mypy but also won’t hurt it. Until mypy has support for it the pydantic extension should continue to be used.