class, unit)[source]

Trigger based on a fixed interval.

This trigger accepts iterations divided by a given interval. There are two ways to specify the interval: per iterations and epochs. Iteration means the number of updates, while epoch means the number of sweeps over the training dataset. Fractional values are allowed if the interval is a number of epochs; the trigger uses the iteration and epoch_detail attributes defined by the updater.

For the description of triggers, see get_trigger().

  • period (int or float) – Length of the interval. Must be an integer if unit is 'iteration'.

  • unit (str) – Unit of the length specified by period. It must be either 'iteration' or 'epoch'.



Decides whether the extension should be called on this iteration.


trainer (Trainer) – Trainer object that this trigger is associated with. The updater associated with this trainer is used to determine if the trigger should fire.


True if the corresponding extension should be invoked in this iteration.

Return type


__eq__(value, /)

Return self==value.

__ne__(value, /)

Return self!=value.

__lt__(value, /)

Return self<value.

__le__(value, /)

Return self<=value.

__gt__(value, /)

Return self>value.

__ge__(value, /)

Return self>=value.