lenskit.basic.bias.BiasScorer
=============================

.. py:class:: lenskit.basic.bias.BiasScorer(config = None, **kwargs)
   

   Bases: :py:obj:`lenskit.pipeline.components.Component`\ [\ :py:obj:`lenskit.data.ItemList`\ ], :py:obj:`lenskit.training.Trainable`


   A user-item bias rating prediction model.  This component uses
   :class:`BiasModel` to predict ratings for users and items.

   :param config: The component configuration.

   :Stability: Caller


   .. py:attribute:: config
      :type:  BiasConfig

      The component configuration object.  Component classes that support
      configuration **must** redefine this attribute with their specific
      configuration class type, which can be a Python dataclass or a Pydantic
      model class.


   .. py:attribute:: model
      :type:  BiasModel


   .. py:method:: is_trained()

      Query if this component has already been trained.



   .. py:method:: train(data, options = TrainingOptions())

      Train the bias model on some rating data.

      :param ratings: The training data (must have ratings).

      :returns: The trained bias object.



   .. py:method:: __call__(query, items)

      Compute predictions for a user and items.  Unknown users and items are
      assumed to have zero bias.

      :param query: The recommendation query.  If the query has an item list with
                    ratings, those ratings are used to compute a new bias instead of
                    using the user's historical bias.
      :param items: The items to score.

      :returns: Scores for `items`.