chainer.training.extensions.snapshot_object¶
- chainer.training.extensions.snapshot_object(target, filename, savefun=None, *, condition=None, writer=None, snapshot_on_error=False, n_retains=- 1, autoload=False)[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.
- Parameters
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.
condition – Condition object. It must be a callable object that returns boolean without any arguments. If it returns
True
, the snapshot will be done. If not, it will be skipped. The default is a function that always returnsTrue
.writer – Writer object. It must be a callable object. See below for the list of built-in writers. If
savefun
is other thanNone
, this argument must beNone
. In that case, aSimpleWriter
object instantiated with specifiedsavefun
argument will be used.snapshot_on_error (bool) – Whether to take a snapshot in case trainer loop has been failed.
n_retains (int) – Number of snapshot files to retain through the cleanup. Must be a positive integer for any cleanup to take place. Automatic deletion of old snapshots only works when the filename is string.
num_retain (int) – Same as
n_retains
(deprecated).autoload (bool) – With this enabled, the extension automatically finds the latest snapshot and loads the data to the target. Automatic loading only works when the filename is a string.
- Returns
Snapshot extension object.