zarr-indexing 0.1.0

Composable, lazy coordinate transforms for Zarr array indexing.

zarr-indexing

Composable, lazy coordinate transforms for Zarr array indexing.

Documentation: https://zarr-indexing.readthedocs.io/

This package implements TensorStore-inspired index transforms. The core idea: every indexing operation (slicing, fancy indexing, etc.) produces a coordinate mapping from user space to storage space. These mappings compose lazily — no I/O until you explicitly read or write.

Key types:

• IndexDomain — a rectangular region of integer coordinates
• IndexTransform — maps input coordinates to storage coordinates
• ConstantMap, DimensionMap, ArrayMap — the three ways a single output dimension can depend on the input
• compose — chain two transforms into one

The package depends only on NumPy and the standard library; it does not import zarr. It is developed in the zarr-python repository and consumed by zarr to resolve array indexing operations.

Installation

pip install zarr-indexing

Developing

Package-scoped development commands live in the justfile (requires just):

just test        # run the test suite (extra args go to pytest)
just lint        # ruff, same invocation as CI
just typecheck   # pyright, same invocation as CI
just docs-check  # strict build of the docs site
just check       # all of the above
just docs-serve  # serve the docs site locally

Run them from this directory, or from anywhere in the repository as just packages/zarr-indexing/<recipe>.

The test recipe runs against the workspace-root environment, because the chunk-resolution tests exercise this package against zarr's chunk grids and zarr is deliberately not a dependency of this package.

License

MIT