lenskit.data.EntityAttribute
============================

.. py:class:: lenskit.data.EntityAttribute(name, spec, table, vocab, rows)
   :canonical: lenskit.data._attributes.EntityAttribute

   Bases: :py:obj:`abc.ABC`


   Base class for an attribute associated with an entity class.  This class
   effectively represents a _column_ of a data table of entities: the attribute
   values for one or more entities.  In that regard, it is similar to a Pandas
   series: it records entity IDs/numbers, like an index, and associated
   attribute values.

   This is the general interface for all entity attributes.  Not all access
   methods are supported for all layouts.

   :Stability: caller


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

      The name of the attribute.


   .. py:attribute:: layout
      :type:  lenskit.data.schema.AttrLayout

      The attribute layout.


   .. py:property:: data_type
      :type: pyarrow.DataType

      :abstractmethod:


      Get the data type of this attribute set.


   .. py:method:: ids()

      Get the entity IDs for this collection of entities.



   .. py:method:: id_index()

      Get the entity IDs as a Pandas index.



   .. py:method:: numbers()

      Get the entity numbers for the attributes



   .. py:method:: cat_matrix(*, normalize = None)
      :abstractmethod:


      Compute a categorical matrix representation of the attribute.

      :param normalize: Optional normalization method.
                        "unit": Normalize each row to unit length.
                        "distribution": Normalize each row so elements sum to 1

      :returns:

                A tuple containing:
                    matrix (numpy.ndarray or scipy.sparse.csr_array): The categorical matrix.
                    vocab (Vocabulary or None): The vocabulary associated with the categories.
      :rtype: tuple



   .. py:property:: dim_names
      :type: list[str] | None


      Get the names attached to this attribute's dimensions.

      .. note::

          Only applicable to vector and sparse attributes.


   .. py:property:: is_scalar
      :type: bool


      Query whether this attribute is scalar.


   .. py:property:: is_list
      :type: bool


      Query whether this attribute is a list.


   .. py:property:: is_vector
      :type: bool


      Query whether this attribute is a dense vector.


   .. py:property:: is_sparse
      :type: bool


      Query whether this attribute is a sparse vector.


   .. py:method:: pandas(*, missing = 'null')
      :abstractmethod:



   .. py:method:: numpy()

      Get the attribute values as a NumPy array.

      .. note::
          Undefined attribute values may have undefined contents; they will
          _usually_ be ``NaN`` or similar, but this is not fully guaranteed.



   .. py:method:: arrow()

      Get the attribute values as an Arrow array.



   .. py:method:: scipy()

      Get this attribute as a SciPy sparse array (if it is sparse), or a NumPy
      array if it is dense.



   .. py:method:: torch()


   .. py:method:: drop_null()

      Subset this attribute set to only entities for which it is defined.



   .. py:method:: __len__()