# optuna.structs¶

class optuna.structs.TrialState(value)[source]

State of a Trial.

RUNNING

The Trial is running.

COMPLETE

The Trial has been finished without any error.

PRUNED

The Trial has been pruned with TrialPruned.

FAIL

The Trial has failed due to an uncaught error.

Deprecated since version 1.4.0: This class is deprecated. Please use TrialState instead.

class optuna.structs.StudyDirection(value)[source]

Direction of a Study.

NOT_SET

Direction has not been set.

MINIMIZE

Study minimizes the objective function.

MAXIMIZE

Study maximizes the objective function.

Deprecated since version 1.4.0: This class is deprecated. Please use StudyDirection instead.

class optuna.structs.FrozenTrial(*args, **kwargs)[source]

Status and results of a Trial.

number

Unique and consecutive number of Trial for each Study. Note that this field uses zero-based numbering.

state
value

Objective value of the Trial.

datetime_start

Datetime where the Trial started.

datetime_complete

Datetime where the Trial finished.

params

Dictionary that contains suggested parameters.

user_attrs

Dictionary that contains the attributes of the Trial set with optuna.trial.Trial.set_user_attr().

intermediate_values

Intermediate objective values set with optuna.trial.Trial.report().

Warning

Deprecated in v1.4.0. This feature will be removed in the future. The removal of this feature is currently scheduled for v3.0.0, but this schedule is subject to change. See https://github.com/optuna/optuna/releases/tag/v1.4.0.

This class was moved to trial. Please use FrozenTrial instead.

property distributions

Dictionary that contains the distributions of params.

property duration

Return the elapsed time taken to complete the trial.

Returns

The duration.

class optuna.structs.StudySummary(*args, **kwargs)[source]

Basic attributes and aggregated results of a Study.

study_name

Name of the Study.

direction
best_trial

FrozenTrial with best objective value in the Study.

user_attrs

Dictionary that contains the attributes of the Study set with optuna.study.Study.set_user_attr().

system_attrs

Dictionary that contains the attributes of the Study internally set by Optuna.

n_trials

The number of trials ran in the Study.

datetime_start

Datetime where the Study started.

Warning

Deprecated in v1.4.0. This feature will be removed in the future. The removal of this feature is currently scheduled for v3.0.0, but this schedule is subject to change. See https://github.com/optuna/optuna/releases/tag/v1.4.0.

This class was moved to study. Please use StudySummary instead.