ce ](polars.api.register_expr_namespace.html)
    * [ polars.api.register_dataframe_namespace ](polars.api.register_dataframe_namespace.html)
    * [ polars.api.register_lazyframe_namespace ](polars.api.register_lazyframe_namespace.html)
    * [ polars.api.register_series_namespace ](polars.api.register_series_namespace.html)

  * [ Plugins ](../plugins.html)

  * [ SQL Interface ](../sql.html) __
    * [ polars.SQLContext.execute ](polars.SQLContext.execute.html)
    * [ polars.SQLContext.register ](polars.SQLContext.register.html)
    * [ polars.SQLContext.register_globals ](polars.SQLContext.register_globals.html)
    * [ polars.SQLContext.register_many ](polars.SQLContext.register_many.html)
    * [ polars.SQLContext.unregister ](polars.SQLContext.unregister.html)
    * [ polars.SQLContext.tables ](polars.SQLContext.tables.html)

  * [ Exceptions ](../exceptions.html) __
    * [ polars.exceptions.ArrowError ](polars.exceptions.ArrowError.html)
    * [ polars.exceptions.ColumnNotFoundError ](polars.exceptions.ColumnNotFoundError.html)
    * [ polars.exceptions.ComputeError ](polars.exceptions.ComputeError.html)
    * [ polars.exceptions.DuplicateError ](polars.exceptions.DuplicateError.html)
    * [ polars.exceptions.InvalidOperationError ](polars.exceptions.InvalidOperationError.html)
    * [ polars.exceptions.NoDataError ](polars.exceptions.NoDataError.html)
    * [ polars.exceptions.NoRowsReturnedError ](polars.exceptions.NoRowsReturnedError.html)
    * [ polars.exceptions.PolarsError ](polars.exceptions.PolarsError.html)
    * [ polars.exceptions.PolarsPanicError ](polars.exceptions.PolarsPanicError.html)
    * [ polars.exceptions.RowsError ](polars.exceptions.RowsError.html)
    * [ polars.exceptions.SchemaError ](polars.exceptions.SchemaError.html)
    * [ polars.exceptions.SchemaFieldNotFoundError ](polars.exceptions.SchemaFieldNotFoundError.html)
    * [ polars.exceptions.ShapeError ](polars.exceptions.ShapeError.html)
    * [ polars.exceptions.StructFieldNotFoundError ](polars.exceptions.StructFieldNotFoundError.html)
    * [ polars.exceptions.TooManyRowsReturnedError ](polars.exceptions.TooManyRowsReturnedError.html)

  * [ Testing ](../testing.html) __
    * [ polars.testing.assert_frame_equal ](polars.testing.assert_frame_equal.html)
    * [ polars.testing.assert_frame_not_equal ](polars.testing.assert_frame_not_equal.html)
    * [ polars.testing.assert_series_equal ](polars.testing.assert_series_equal.html)
    * [ polars.testing.assert_series_not_equal ](polars.testing.assert_series_not_equal.html)
    * [ polars.testing.parametric.dataframes ](polars.testing.parametric.dataframes.html)
    * [ polars.testing.parametric.series ](polars.testing.parametric.series.html)
    * [ polars.testing.parametric.column ](polars.testing.parametric.column.html)
    * [ polars.testing.parametric.columns ](polars.testing.parametric.columns.html)
    * [ polars.testing.parametric.create_list_strategy ](polars.testing.parametric.create_list_strategy.html)
    * [ polars.testing.parametric.load_profile ](polars.testing.parametric.load_profile.html)
    * [ polars.testing.parametric.set_profile ](polars.testing.parametric.set_profile.html)

  * [ Metadata ](../metadata.html) __
    * [ polars.build_info ](polars.build_info.html)
    * [ polars.get_index_type ](polars.get_index_type.html)
    * [ polars.show_versions ](polars.show_versions.html)
    * [ polars.thread_pool_size ](polars.thread_pool_size.html)
    * [ polars.threadpool_size ](polars.threadpool_size.html)

  * [ __ ](../../index.html)
  * [ Python API reference ](../index.html)
  * [ Data types ](../datatypes.html)
  * polars.datat... 

#  polars.datatypes.Categorical  #

_ class  _ polars.datatypes.  Categorical  (  _ ordering  :  CategoricalOrdering  |  [ None  ](https://docs.python.org/3/library/constants.html#None "\(in Python v3.12\)") =  'physical'  _ )  [ [source]  ](https://github.com/pola-rs/polars/blob/main/py-polars/polars/datatypes/classes.py#L533-L565) #