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vernier.adapters

Drop-in shims for migrating from competing tools without rewriting the call sites. Today: a pycocotools COCOeval adapter; future shims slot in here.

Framework adapters for vernier.

This subpackage holds optional integrations with external frameworks (PyTorch tensors via DLPack, etc.) and migration helpers. Each adapter is importable without its underlying framework being installed; gate framework-specific imports behind try/except ImportError.

The pycocotools migration helper (:func:patch_pycocotools) is the sanctioned entry point for swapping pycocotools.cocoeval.COCOeval with vernier's drop-in. Policy and rationale are in ADR-0007.

patch_pycocotools 

patch_pycocotools(
    parity_mode: ParityMode = "strict",
) -> Callable[[], None]

Replace pycocotools.cocoeval.COCOeval with vernier's drop-in.

Returns an idempotent unpatch callable. The outermost unpatch restores the original pycocotools class; intermediate unpatches pop the parity-mode stack so nested :func:patched_pycocotools exits restore the surrounding patch state. Per ADR-0007:

  • Default parity_mode is "strict" because migration intent is bit-exactness with pycocotools.
  • Raises :class:ImportError if pycocotools is not installed — silent fallthrough would let downstream test setups think the patch took effect when it did not.
  • Calling patch_pycocotools repeatedly without unpatching stacks the parity-mode state but never overwrites the saved original class, so the final unpatch always restores the real pycocotools class.

Not thread-safe — call once at process or test setup, unwind at teardown. The patch must fire before any module that imports pycocotools.cocoeval — see docs/migrate/from-pycocotools.md §"Troubleshooting" for the import-order pitfall and the session-scoped pytest fixture that side-steps it.

patched_pycocotools 

patched_pycocotools(
    parity_mode: ParityMode = "strict",
) -> Generator[None, None, None]

Context-manager variant of :func:patch_pycocotools.

Nests correctly: an outer with followed by an inner with restores the outer-patch state on inner exit and the original pycocotools class on outer exit (per ADR-0007 §"Reentrancy").