phenotypic.sdk_.master_carries_user_metadata

phenotypic.sdk_.master_carries_user_metadata(frame: pl.DataFrame) → bool

Return whether this master predates the §7.3 inversion.

The one genuinely dangerous failure mode in §7 is a reader that filters or groups a master on a user-metadata column: against a v2 master that returns empty rather than raising. This predicate is what such a reader branches on.

A v1 run that was given no --metadata is indistinguishable from a v2 run by this test, and that is expected to be harmless – neither has anything to join. test_a_v1_metadata_free_master_is_indistinguishable_from_v2 is the designated falsifier for that expectation.

Parameters:

frame (pl.DataFrame) – A master measurements frame.

Returns:

True when the frame carries at least one user-metadata column.

Return type:

bool