AnnData Overview AnnData is a Python package for handling annotated data matrices, storing experimental measurements (X) alongside observation metadata (obs), variable metadata (var), and multi-dimensional annotations (obsm, varm, obsp, varp, uns). Originally designed for single-cell genomics through Scanpy, it now serves as a general-purpose framework for any annotated data requiring efficient storage, manipulation, and analysis. When to Use This Skill Use this skill when: - Creating, reading, or writing AnnData objects - Working with h5ad, zarr, or other genomics data formats - Performing s…