Motivation

Description of the changes

• Added private method _get_best_trial(deepcopy: bool = True)
• Modified best_trial property to call _get_best_trial(deepcopy=True)
• Updated _log_completed_trial to use _get_best_trial(deepcopy=False)

Performance

Example code execution time improved from 1.5650s → 1.2588s

import optuna
def objective(trial):
    x = trial.suggest_float("x", -1, 1)
    y = trial.suggest_int("y", -1, 1)
    return x**2 + y

study = optuna.create_study(sampler=optuna.samplers.RandomSampler())
study.optimize(objective, n_trials=10000)