optuna 0.19.0

v0.19.0

on Python PyPI

This is the release note of v0.19.0. See here for the complete list of solved issues and merged PRs.

Highlights

The GitHub organization of this repository has been changed from pfnet, the organization for Preferred Networks, Inc. to optuna in order to widen the community, growing the project as an open source software.

optuna.exceptions has been introduced. Now, all exceptions defined in Optuna, including TrialPruned, have been moved out from optuna.structs to this new submodule. This is a part of a larger refactoring that we are currently working on to clean up the interfaces and make Optuna even easier to use. To avoid breaking existing code however, optuna.structs.TrialPruned is still available but marked as deprecated.

Upcoming Python 2 Support Drop

Due to the end-of-life (EOL) of Python 2 in January 2020, Optuna will drop Python 2 support in December 2019.
This decision was made considering the following facts:

• Python 2 goes end-of-life (EOL) in January 2020.
• Many scientific computation packages, including NumPy, which is one of the core dependency of Optuna, are planning or already started to drop support for Python 2.
  We plan to drop Python 2 support in the first release in December 2019.

Compatibility

• Disallow negative step numbers in Trial.report. (#701)
• Disallow erroneous arguments to PercentilePruner. (#693)
• Extract exception classes to optuna.exceptions module. (#691)
• Make {FrozenTrial,Trial}.trial_id private. (#663)

New Features

• Allow specifying step interval for {Median,Percentile}Pruner. (#660)

Enhancements

• Make distribution classes single inheritance. (#573)

Bug Fixes

• Fix the handling of time_budget option on lightgbm_tuner.train(). (#684, thanks @momijiame!)

Documents

• Improve documentation of Trial.should_prune. (#690)
• Expose RDBStorage constructor. (#689)
• Add a note about type casting of reported values to trial.report() doc. (#687)
• Add punctuation to copyright in docs. (#682)
• Replace the company name with Optuna Contributors in the docs. (#676)
• Update the documentation of Trial class. (#668)
• Add Code of Conduct. (#675, thanks @Crissman!)

Examples

• Improve visualization examples. (#667, thanks @Crissman!)
• Update PyTorch Lightning example for pytorch-lightning==0.5.3. (#700)

Tests

• Add more optuna.visualization tests. (#630, thanks @crcrpar!)
• Remove the version constraint for pytorch_lightning. (#694)