---

name: v2-components description: "Guides Waymo Open Dataset V2 columnar components, Parquet tags, dataclass schemas, object assets, and Pandas or Dask dataframe joins." disable-model-invocation: true metadata: disco-role: operating license: NOASSERTION

V2 Components

Use this sub-skill when the task mentions WOD V2, Perception 2.0, component tags, Parquet component directories, Component dataclasses, flattened dictionaries, Arrow schemas, v2.merge, Pandas/Dask key joins, or object-asset V2 structures.

Read:

• references/api-reference.md for verified signatures, component tags, dataclass rules, and exported helpers.
• references/workflows.md for component flatten/unflatten, schema, Parquet, and merge recipes.
• references/troubleshooting.md for key-column mismatches, repeated-field columns, PyArrow/Pandas/Dask issues, and object-asset pitfalls.

Useful bundled check:

• scripts/inspect_v2_components.py lists installed V2 tags, validates a tiny component schema, and runs a one-row v2.merge check.

Route elsewhere:

• Use dataset-utils for v1 TFRecord Frame parsing, range images, camera projections, maps, or point clouds.
• Use metrics-evaluation for detection/tracking/motion metric wrappers and submission scoring.
• Use camera-and-segmentation for camera-only challenge, PVPS, semantic segmentation, or Deeplab2 camera-segmentation issues.

Typical flow:

1. Verify the package with the root environment checker or this sub-skill script.
2. Identify component tags with v2.ALL_TAGS or v2.TAG_BY_COMPONENT.
3. For custom or reconstructed records, use Component.to_flatten_dict(), Component.from_dict(), and Component.schema() rather than inventing column names.
4. Merge component tables with v2.merge(left, right, left_nullable=..., right_nullable=..., left_group=..., right_group=...) and check key prefixes before joining.