deephyper.contrib.callbacks.time_stopping.Callback

deephyper.contrib.callbacks.time_stopping.Callback

class deephyper.contrib.callbacks.time_stopping.Callback[source]

Bases: object

Abstract base class used to build new callbacks.

Callbacks can be passed to keras methods such as fit, evaluate, and predict in order to hook into the various stages of the model training and inference lifecycle.

To create a custom callback, subclass keras.callbacks.Callback and override the method associated with the stage of interest. See https://www.tensorflow.org/guide/keras/custom_callback for more information.

Example:

>>> training_finished = False
>>> class MyCallback(tf.keras.callbacks.Callback):
...   def on_train_end(self, logs=None):
...     global training_finished
...     training_finished = True
>>> model = tf.keras.Sequential([tf.keras.layers.Dense(1, input_shape=(1,))])
>>> model.compile(loss='mean_squared_error')
>>> model.fit(tf.constant([[1.0]]), tf.constant([[1.0]]),
...           callbacks=[MyCallback()])
>>> assert training_finished == True

If you want to use Callback objects in a custom training loop:

  1. You should pack all your callbacks into a single callbacks.CallbackList so they can all be called together.

  2. You will need to manually call all the on_* methods at the apropriate locations in your loop. Like this:

    ``` callbacks = tf.keras.callbacks.CallbackList([…]) callbacks.append(…)

    callbacks.on_train_begin(…) for epoch in range(EPOCHS):

    callbacks.on_epoch_begin(epoch) for i, data in dataset.enumerate():

    callbacks.on_train_batch_begin(i) batch_logs = model.train_step(data) callbacks.on_train_batch_end(i, batch_logs)

    epoch_logs = … callbacks.on_epoch_end(epoch, epoch_logs)

    final_logs=… callbacks.on_train_end(final_logs) ```

params

Dict. Training parameters (eg. verbosity, batch size, number of epochs…).

model

Instance of keras.models.Model. Reference of the model being trained.

The logs dictionary that callback methods take as argument will contain keys for quantities relevant to the current batch or epoch (see method-specific docstrings).

Methods

on_batch_begin

A backwards compatibility alias for on_train_batch_begin.

on_batch_end

A backwards compatibility alias for on_train_batch_end.

on_epoch_begin

Called at the start of an epoch.

on_epoch_end

Called at the end of an epoch.

on_predict_batch_begin

Called at the beginning of a batch in predict methods.

on_predict_batch_end

Called at the end of a batch in predict methods.

on_predict_begin

Called at the beginning of prediction.

on_predict_end

Called at the end of prediction.

on_test_batch_begin

Called at the beginning of a batch in evaluate methods.

on_test_batch_end

Called at the end of a batch in evaluate methods.

on_test_begin

Called at the beginning of evaluation or validation.

on_test_end

Called at the end of evaluation or validation.

on_train_batch_begin

Called at the beginning of a training batch in fit methods.

on_train_batch_end

Called at the end of a training batch in fit methods.

on_train_begin

Called at the beginning of training.

on_train_end

Called at the end of training.

set_model

set_params

on_batch_begin(batch, logs=None)[source]

A backwards compatibility alias for on_train_batch_begin.

on_batch_end(batch, logs=None)[source]

A backwards compatibility alias for on_train_batch_end.

on_epoch_begin(epoch, logs=None)[source]

Called at the start of an epoch.

Subclasses should override for any actions to run. This function should only be called during TRAIN mode.

Parameters
  • epoch – Integer, index of epoch.

  • logs – Dict. Currently no data is passed to this argument for this method but that may change in the future.

on_epoch_end(epoch, logs=None)[source]

Called at the end of an epoch.

Subclasses should override for any actions to run. This function should only be called during TRAIN mode.

Parameters
  • epoch – Integer, index of epoch.

  • logs

    Dict, metric results for this training epoch, and for the

    validation epoch if validation is performed. Validation result keys are prefixed with val_. For training epoch, the values of the

    Model’s metrics are returned. Example`{‘loss’: 0.2, ‘accuracy’:

    0.7}`.

on_predict_batch_begin(batch, logs=None)[source]

Called at the beginning of a batch in predict methods.

Subclasses should override for any actions to run.

Note that if the steps_per_execution argument to compile in tf.keras.Model is set to N, this method will only be called every N batches.

Parameters
  • batch – Integer, index of batch within the current epoch.

  • logs – Dict. Currently no data is passed to this argument for this method but that may change in the future.

on_predict_batch_end(batch, logs=None)[source]

Called at the end of a batch in predict methods.

Subclasses should override for any actions to run.

Note that if the steps_per_execution argument to compile in tf.keras.Model is set to N, this method will only be called every N batches.

Parameters
  • batch – Integer, index of batch within the current epoch.

  • logs – Dict. Aggregated metric results up until this batch.

on_predict_begin(logs=None)[source]

Called at the beginning of prediction.

Subclasses should override for any actions to run.

Parameters

logs – Dict. Currently no data is passed to this argument for this method but that may change in the future.

on_predict_end(logs=None)[source]

Called at the end of prediction.

Subclasses should override for any actions to run.

Parameters

logs – Dict. Currently no data is passed to this argument for this method but that may change in the future.

on_test_batch_begin(batch, logs=None)[source]

Called at the beginning of a batch in evaluate methods.

Also called at the beginning of a validation batch in the fit methods, if validation data is provided.

Subclasses should override for any actions to run.

Note that if the steps_per_execution argument to compile in tf.keras.Model is set to N, this method will only be called every N batches.

Parameters
  • batch – Integer, index of batch within the current epoch.

  • logs – Dict. Currently no data is passed to this argument for this method but that may change in the future.

on_test_batch_end(batch, logs=None)[source]

Called at the end of a batch in evaluate methods.

Also called at the end of a validation batch in the fit methods, if validation data is provided.

Subclasses should override for any actions to run.

Note that if the steps_per_execution argument to compile in tf.keras.Model is set to N, this method will only be called every N batches.

Parameters
  • batch – Integer, index of batch within the current epoch.

  • logs – Dict. Aggregated metric results up until this batch.

on_test_begin(logs=None)[source]

Called at the beginning of evaluation or validation.

Subclasses should override for any actions to run.

Parameters

logs – Dict. Currently no data is passed to this argument for this method but that may change in the future.

on_test_end(logs=None)[source]

Called at the end of evaluation or validation.

Subclasses should override for any actions to run.

Parameters

logs – Dict. Currently the output of the last call to on_test_batch_end() is passed to this argument for this method but that may change in the future.

on_train_batch_begin(batch, logs=None)[source]

Called at the beginning of a training batch in fit methods.

Subclasses should override for any actions to run.

Note that if the steps_per_execution argument to compile in tf.keras.Model is set to N, this method will only be called every N batches.

Parameters
  • batch – Integer, index of batch within the current epoch.

  • logs – Dict. Currently no data is passed to this argument for this method but that may change in the future.

on_train_batch_end(batch, logs=None)[source]

Called at the end of a training batch in fit methods.

Subclasses should override for any actions to run.

Note that if the steps_per_execution argument to compile in tf.keras.Model is set to N, this method will only be called every N batches.

Parameters
  • batch – Integer, index of batch within the current epoch.

  • logs – Dict. Aggregated metric results up until this batch.

on_train_begin(logs=None)[source]

Called at the beginning of training.

Subclasses should override for any actions to run.

Parameters

logs – Dict. Currently no data is passed to this argument for this method but that may change in the future.

on_train_end(logs=None)[source]

Called at the end of training.

Subclasses should override for any actions to run.

Parameters

logs – Dict. Currently the output of the last call to on_epoch_end() is passed to this argument for this method but that may change in the future.