Data Abstractions#

The lenskit.data module provides the core data abstractions LensKit uses to represent recommender system inputs and outputs.

Data Sets#

`Dataset`	Representation of a data set for LensKit training, evaluation, etc.
`EntitySet`	Representation of a set of entities from the dataset.
`AttributeSet`	Base class for attributes associated with entities.
`RelationshipSet`	Representation for a set of relationship records.
`MatrixRelationshipSet`	Two-entity relationships without duplicates, accessible in matrix form.
`CSRStructure`	Representation of the compressed sparse row structure of a sparse matrix, without any data values.

`DatasetBuilder`	Construct data sets from data and tables.
`from_interactions_df`	Create a dataset from a data frame of ratings or other user-item interactions.
`load_movielens`	Load a MovieLens dataset.
`load_movielens_df`	Load the ratings from a MovieLens dataset as a raw data frame.

`ItemList`	Representation of a (usually ordered) list of items, possibly with scores and other associated data; many components take and return item lists.
`ItemListCollection`	A collection of item lists.
`ItemListCollector`	Collect item lists with associated keys, as in `ItemListCollection`.
`ListILC`	Mutable item list collection backed by a Python list.
`UserIDKey`	Key type for user IDs.
`GenericKey`	Built-in immutable sequence.
`MutableItemListCollection`	Intersection type of `ItemListCollection` and `ItemListCollector`.

`RecQuery`	Representation of a the data available for a recommendation query.
`QueryInput`	Represent a PEP 604 union type

`lenskit.data.schema`	Pydantic models for LensKit data schemas.
`Vocabulary`	Vocabularies of entity identifiers for the LensKit data model.

These classes provide support for compressed sparse row matrices in Arrow.

`SparseRowType`	Data type for sparse rows stored in Arrow.
`SparseIndexType`	Data type for the index field of a sparse row. Indexes are just stored as ``int32``s; the extension type attaches the row's dimensionality to the index field (making it easier to pass it to/from Rust, since we often pass arrays and not entire fields).
`SparseRowArray`	An array of sparse rows (a compressed sparse row matrix).

They are also supported on the Rust side of LensKit.