tf.keras.backend.in_train_phase

TensorFlow 2 version View source on GitHub

Selects x in train phase, and alt otherwise.

Note that alt should have the same shape as x.

x What to return in train phase (tensor or callable that returns a tensor).
alt What to return otherwise (tensor or callable that returns a tensor).
training Optional scalar tensor (or Python boolean, or Python integer) specifying the learning phase.

Either x or alt based on the training flag. the training flag defaults to K.learning_phase().