Tune Callbacks (tune.Callback)

See this user guide for more details.

See also

Tune’s built-in loggers use the Callback interface.

Callback Interface

Callback Initialization and Setup

Callback()

Tune base callback that can be extended and passed to a TrialRunner

Callback.setup([stop, num_samples, ...])

Called once at the very beginning of training.

Callback Hooks

Callback.on_checkpoint(iteration, trials, ...)	Called after a trial saved a checkpoint with Tune.
Callback.on_experiment_end(trials, **info)	Called after experiment is over and all trials have concluded.
Callback.on_step_begin(iteration, trials, **info)	Called at the start of each tuning loop step.
Callback.on_step_end(iteration, trials, **info)	Called at the end of each tuning loop step.
Callback.on_trial_complete(iteration, ...)	Called after a trial instance completed.
Callback.on_trial_error(iteration, trials, ...)	Called after a trial instance failed (errored).
Callback.on_trial_restore(iteration, trials, ...)	Called after restoring a trial instance.
Callback.on_trial_result(iteration, trials, ...)	Called after receiving a result from a trial.
Callback.on_trial_save(iteration, trials, ...)	Called after receiving a checkpoint from a trial.
Callback.on_trial_start(iteration, trials, ...)	Called after starting a trial instance.

Stateful Callbacks

The following methods must be overriden for stateful callbacks to be saved/restored properly by Tune.

Callback.get_state()	Get the state of the callback.
Callback.set_state(state)	Get the state of the callback.