optuna.study.create_study¶

optuna.study.create_study(storage: Optional[Union[str, optuna.storages._base.BaseStorage]] = None, sampler: Optional[optuna.samplers._base.BaseSampler] = None, pruner: Optional[optuna.pruners._base.BasePruner] = None, study_name: Optional[str] = None, direction: Optional[str] = None, load_if_exists: bool = False, *, directions: Optional[Sequence[str]] = None) → optuna.study.Study [source]¶

Create a new Study.

Example

import optuna


def objective(trial):
    x = trial.suggest_uniform("x", 0, 10)
    return x ** 2


study = optuna.create_study()
study.optimize(objective, n_trials=3)

Parameters

storage –
Database URL. If this argument is set to None, in-memory storage is used, and the Study will not be persistent.

Note

When a database URL is passed, Optuna internally uses SQLAlchemy to handle the database. Please refer to SQLAlchemy’s document for further details. If you want to specify non-default options to SQLAlchemy Engine, you can instantiate RDBStorage with your desired options and pass it to the storage argument instead of a URL.
sampler – A sampler object that implements background algorithm for value suggestion. If None is specified, TPESampler is used as the default. See also samplers.
pruner – A pruner object that decides early stopping of unpromising trials. If None is specified, MedianPruner is used as the default. See also pruners.
study_name – Study’s name. If this argument is set to None, a unique name is generated automatically.
direction –
Direction of optimization. Set minimize for minimization and maximize for maximization.

Note

If none of direction and directions are specified, the direction of the study is set to “minimize”.
directions – A sequence of directions during multi-objective optimization.
load_if_exists – Flag to control the behavior to handle a conflict of study names. In the case where a study named study_name already exists in the storage, a DuplicatedStudyError is raised if load_if_exists is set to False. Otherwise, the creation of the study is skipped, and the existing one is returned.

Returns

A Study object.

Raises

ValueError – If the length of directions is zero. Or, if direction is neither ‘minimize’ nor ‘maximize’ when it is a string. Or, if the element of directions is neither minimize nor maximize. Or, if both direction and directions are specified.