, filename, savefun=<function save_npz>)[source]

Returns a trainer extension to take snapshots of a given object.

This extension serializes the given object and saves it to the output directory.

This extension is called once per epoch by default. To take a snapshot at a different interval, a trigger object specifying the required interval can be passed along with this extension to the extend() method of the trainer.

The default priority is -100, which is lower than that of most built-in extensions.

  • target – Object to serialize.
  • filename (str) – Name of the file into which the object is serialized. It can be a format string, where the trainer object is passed to the str.format() method. For example, 'snapshot_{.updater.iteration}' is converted to 'snapshot_10000' at the 10,000th iteration.
  • savefun – Function to save the object. It takes two arguments: the output file path and the object to serialize.

An extension function.