TypedDict mangles private names as regular Python classes do. So, __schema name will become _IntrospectionQuery__schema instead. But, inline definition will preserve a correct name for the field. See python/cpython#129567

Found during python/mypy#16715

Thanks for reporting and the PR. Is this also a problem with current mypy versions? If yes, how can I provoke a typing error there?

Not until python/mypy#16715 is merged

CodSpeed Performance Report

Merging #234 will not alter performance

_{Comparing sobolevn:-1 (e5d09fa) with main (44334f3)}

Summary

✅ 14 untouched benchmarks

Looks good, but you need to silence the linter with # noqa: UP013 because it prefers class syntax, and add a small comment as explanation why we deviate from the class syntax here.

Now there are only mypy issues, probably because mypy has been updated and not related to this PR. Will fix them separately.