Optuna: A hyperparameter optimization framework

Optuna is an automatic hyperparameter optimization software framework, particularly designed for machine learning. It features an imperative, define-by-run style user API. Thanks to our define-by-run API, the code written with Optuna enjoys high modularity, and the user of Optuna can dynamically construct the search spaces for the hyperparameters.

Key Features

Optuna has modern functionalities as follows:

• Lightweight, versatile, and platform agnostic architecture

• Handle a wide variety of tasks with a simple installation that has few requirements.

• Pythonic search spaces

• Define search spaces using familiar Python syntax including conditionals and loops.

• Efficient optimization algorithms

• Adopt state-of-the-art algorithms for sampling hyperparameters and efficiently pruning unpromising trials.

• Easy parallelization

• Scale studies to tens or hundreds of workers with little or no changes to the code.

• Quick visualization

• Inspect optimization histories from a variety of plotting functions.