polars.datatypes.Categorical

class polars.datatypes.Categorical(
    categories: Categories | str | None = None,
    *,
    ordering: CategoricalOrdering | None = None,
)

A categorical encoding of a set of strings.

Parameters:

categories

The categories used for this type; must be a Categories instance, or a string which is interpreted as the name of a Categories. If not provided, the global categories (pl.Categories()) are used.

For legacy reasons if the string is either "physical" or "lexical", it is ignored and a warning is issued. If you wish to use a Categories named "physical" or "lexical", please pass it using Categories explicitly.

ordering{‘lexical’, ‘physical’}

This used to specify how this type was ordered, but now does nothing.

Deprecated since version 1.32.0: Parameter is now ignored. Always behaves as if 'lexical' was passed.

See also

Categories

__init__(
    categories: Categories | str | None = None,
    *,
    ordering: CategoricalOrdering | None = None,
) → None

Methods

__init__([categories, ordering])
base_type()	Return this DataType's fundamental/root type class.
from_python(py_type)	Return the Polars data type corresponding to a given Python type.
is_(other)	Check if this DataType is the same as another DataType.
is_decimal()	Check whether the data type is a decimal type.
is_extension()	Check whether the data type is an extension type.
is_float()	Check whether the data type is a floating point type.
is_integer()	Check whether the data type is an integer type.
is_nested()	Check whether the data type is a nested type.
is_numeric()	Check whether the data type is a numeric type.
is_object()	Check whether the data type is an object type.
is_signed_integer()	Check whether the data type is a signed integer type.
is_temporal()	Check whether the data type is a temporal type.
is_unsigned_integer()	Check whether the data type is an unsigned integer type.
to_dtype_expr()	Return a DataTypeExpr with a static DataType.
to_python()	Return the Python type corresponding to this Polars data type.

Attributes

ordering
categories