Use is_valid_field from 1.x for mypy plugin

[DanielNoord]

Change Summary

pydantic/pydantic/utils.py

Lines 696 to 699 in 3ddb509

	def is_valid_field(name: str) -> bool:
	if not name.startswith('_'):
	return True
	return ROOT_KEY == name

This brings the mypy plugin in the v1 namespace in line with how 1.x actually behaved.

Importing this from the pydantic namespace created warnings in our v1/v2 codebase.

Related issue number

No issue, couldn't find one and this seems like a simple enough change.

Checklist

• The pull request title is a good summary of the changes - it will be used in the changelog
• Unit tests for the changes exist > seems unnecessary?
• Tests pass on CI
• Documentation reflects the changes where applicable
• My PR is ready to review, please add a comment including the phrase "please review" to assign reviewers

Selected Reviewer: @sydney-runkle

skip change file check

[codspeed-hq]

CodSpeed Performance Report

Merging #8738 will not alter performance

_{Comparing DanielNoord:patch-1 (bd50c62) with main (3fda9d6)}

Summary

✅ 10 untouched benchmarks

[DanielNoord]

please review

I think the last failing test can be skipped by adding the correct label? It doesn't feel like this requires a changelog?

[dmontagu]

In general I think we want to avoid changing the 1.X module code as much as possible.

Does it not work to change:

from pydantic.utils import is_valid_field

to

from .utils import is_valid_field

?

[DanielNoord]

@dmontagu It should. Added a second commit to fix this, thanks!

Edit: For some reason CI fails. I can't really reproduce that environment locally easily. David would you mind rerunning CI and seeing if that fixes it? I don't see why PyPy3.10 should fail on this..

[sydney-runkle]

Wonderful, thanks!

[DanielNoord]

@sydney-runkle Any reason why this fix is not included in the latest releases? The backport to 1.10.x doesn't really resolve the issue, as the error is actually on the 2.x tags.

[sydney-runkle]

@DanielNoord,

This should be included in 2.7! Thanks for the ping :).