Other Components

LensKit provides a number of other components; they are detailed in the API reference, but a few that are useful in assembling useful pipelines include:

Candidate Selectors

lenskit.basic.UnratedTrainingItemsCandidateSelector	Candidate selector that selects all known items from the training data that do not appear in the request user's history (RecQuery.user_items).
lenskit.basic.AllTrainingItemsCandidateSelector	Candidate selector that selects all known items from the training data.

History Lookup

LensKit pipelines use a history lookup component to obtain user profile data when the recommender is called with only a user ID, so they do not need to repeat that logic in each component.

lenskit.basic.UserTrainingHistoryLookup

Look up a user's history from the training data.