Some callbacks for keras

keras_callbacks.py

from keras.callbacks import ModelCheckpoint

checkpoint_callback = ModelCheckpoint(
    "c3d_v5_chkpt-{epoch:02d}-{val_loss:.2f}-{val_acc:.2f}.hdf5",
    monitor='val_loss',
    verbose=1,
    save_best_only=True,
    save_weights_only=False,
    mode='auto',
    period=1)

from keras.callbacks import LearningRateScheduler
import math

def step_decay(epoch):
    initial_lrate = 0.003
    drop = 0.5
    epochs_drop =  1
    lrate = initial_lrate * math.pow(drop, math.floor((epoch)/epochs_drop))
    return lrate

lrate = LearningRateScheduler(step_decay, verbose=1)