training.py

from keras.callbacks import ModelCheckpoint

checkpoint_inception = ModelCheckpoint(
    save_best_only = True, 
    verbose = 1, 
    filepath = 'saved_models/weights.best.from_inception_resnet_v2.hdf5'
)

model.fit(
    train_features_inception, 
    train_labels, 
    epochs=35, 
    batch_size= 64, 
    validation_data=(valid_features_inception, valid_labels), callbacks=[checkpoint_inception], verbose=1
)