lenskit.data.EntitySet
======================

.. py:class:: lenskit.data.EntitySet(name, schema, vocabulary, table, _sel = None)
   :canonical: lenskit.data._entities.EntitySet

   Representation of a set of entities from the dataset.  Obtained from
   :meth:`Dataset.entities`.

   Client code does not need to construct this class; obtain instances from a
   dataset's :meth:`~lenskit.data.Dataset.entities` method.


   .. py:attribute:: name
      :type:  str

      The name of the entity class for these entities.


   .. py:attribute:: schema
      :type:  lenskit.data.schema.EntitySchema


   .. py:attribute:: vocabulary
      :type:  lenskit.data._vocab.Vocabulary

      The identifier vocabulary for this schema.


   .. py:property:: attributes
      :type: list[str]


      Get the attribute names for this entity class.


   .. py:method:: count()

      Return the number of entities in this entity set.



   .. py:method:: ids()

      Get the identifiers of the entities in this set.  This is returned
      directly as PyArrow array instead of NumPy.



   .. py:method:: numbers()

      Get the numbers (from the vocabulary) for the entities in this set.



   .. py:method:: arrow()

      Get these entities and their attributes as a PyArrow table.



   .. py:method:: pandas()

      Get the entities and their attributes as a Pandas data frame.



   .. py:method:: attribute(name)

      Get values of an attribute for the entites in this entity set.



   .. py:method:: select(*, ids: lenskit.data.types.IDSequence | None = None) -> EntitySet
                  select(*, numbers: numpy.ndarray[tuple[int], numpy.dtype[numpy.integer[Any]]] | pyarrow.IntegerArray[Any] | None = None) -> EntitySet

      Select a subset of the entities in this set.

      .. note::

          The vocabulary is unchanged, so numbers in the resulting set will be
          entity numbers in the dataset's vocabulary.  They are not rearranged
          to be relative to this entity set.

      :param ids: The entity identifiers to select.
      :param numbers: The entity numbers to select.

      :returns: The entity subset.



   .. py:method:: __len__()