lenskit.basic.popularity.PopScorer
==================================

.. py:class:: lenskit.basic.popularity.PopScorer(config = None, **kwargs)
   

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


   Score items by their popularity.  Use with :py:class:`TopN` to get a
   most-popular-items recommender.

   :Stability: Caller


   .. py:attribute:: config
      :type:  PopConfig

      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:: items
      :type:  lenskit.data.Vocabulary

      Vocabulary of known items at training time.


   .. py:attribute:: item_scores
      :type:  numpy.ndarray[tuple[int], numpy.dtype[numpy.float32]]

      Array of per-item popularity scores.


   .. py:method:: is_trained()

      Query if this component has already been trained.



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

      Train the model to learn its parameters from a training dataset.

      :param data: The training dataset.
      :param options: The training options.



   .. py:method:: __call__(items)

      Run the pipeline's operation and produce a result.  This is the key
      method for components to implement.