from __future__ import annotations
from typing import Sequence, Union, overload
from typing_extensions import (Literal, # Move to `typing` when 3.8 minimum
TypeAlias)
from ConfigSpace.hyperparameters import (CategoricalHyperparameter,
OrdinalHyperparameter)
# We only accept these types in `items`
T: TypeAlias = Union[str, int, float]
# ordered False -> CategoricalHyperparameter
@overload
def Categorical(
name: str,
items: Sequence[T],
*,
default: T | None = None,
weights: Sequence[float] | None = None,
ordered: Literal[False],
meta: dict | None = None,
) -> CategoricalHyperparameter:
...
# ordered True -> OrdinalHyperparameter
@overload
def Categorical(
name: str,
items: Sequence[T],
*,
default: T | None = None,
weights: Sequence[float] | None = None,
ordered: Literal[True],
meta: dict | None = None,
) -> OrdinalHyperparameter:
...
# ordered bool (unknown) -> Either
@overload
def Categorical(
name: str,
items: Sequence[T],
*,
default: T | None = None,
weights: Sequence[float] | None = None,
ordered: bool = ...,
meta: dict | None = None,
) -> CategoricalHyperparameter | OrdinalHyperparameter:
...
[docs]def Categorical(
name: str,
items: Sequence[T],
*,
default: T | None = None,
weights: Sequence[float] | None = None,
ordered: bool = False,
meta: dict | None = None,
) -> CategoricalHyperparameter | OrdinalHyperparameter:
"""Creates a Categorical Hyperparameter.
CategoricalHyperparameter's can be used to represent a discrete
choice. Optionally, you can specify that these values are also ordered in
some manner, e.g. ``["small", "medium", "large"]``.
.. code:: python
# A simple categorical hyperparameter
c = Categorical("animals", ["cat", "dog", "mouse"])
# With a default
c = Categorical("animals", ["cat", "dog", "mouse"], default="mouse")
# Make them weighted
c = Categorical("animals", ["cat", "dog", "mouse"], weights=[0.1, 0.8, 3.14])
# Specify it's an OrdinalHyperparameter (ordered categories)
# ... note that you can't apply weights to an Ordinal
o = Categorical("size", ["small", "medium", "large"], ordered=True)
# Add some meta information for your own tracking
c = Categorical("animals", ["cat", "dog", "mouse"], meta={"use": "Favourite Animal"})
Note
----
``Categorical`` is actually a function, please use the corresponding return types if
doing an `isinstance(param, type)` check with either
:py:class:`~ConfigSpace.hyperparameters.CategoricalHyperparameter`
and/or :py:class:`~ConfigSpace.hyperparameters.OrdinalHyperparameter`.
Parameters
----------
name: str
The name of the hyperparameter
items: Sequence[T],
A list of items to put in the category. Note that there are limitations:
* Can't use `None`, use a string "None" instead and convert as required.
* Can't have duplicate categories, use weights if required.
default: T | None = None
The default value of the categorical hyperparameter
weights: Sequence[float] | None = None
The weights to apply to each categorical. Each item will be sampled according
to these weights.
ordered: bool = False
Whether the categorical is ordered or not. If True, this will return an
:py:class:`OrdinalHyperparameter`, otherwise it remain a
:py:class:`CategoricalHyperparameter`.
meta: dict | None = None
Any additional meta information you would like to store along with the hyperparamter.
"""
if ordered and weights is not None:
raise ValueError("Can't apply `weights` to `ordered` Categorical")
if ordered:
return OrdinalHyperparameter(
name=name,
sequence=items,
default_value=default,
meta=meta,
)
else:
return CategoricalHyperparameter(
name=name,
choices=items,
default_value=default,
weights=weights,
meta=meta,
)
