run3.py

#
# New generator with file path list in DataFrame.
#
from akmtdfgen import get_demo_data
from akmtdfgen import generator_from_df

df_train, df_valid = get_demo_data()

target_size = (img_width, img_height)
train_generator = generator_from_df(df_train, batch_size, target_size)
validation_generator = generator_from_df(df_valid, batch_size, target_size)

nbatches_train, mod = divmod(df_train.shape[0], batch_size)
nbatches_valid, mod = divmod(df_valid.shape[0], batch_size)

nworkers = 10

model.fit_generator(
    train_generator,
    steps_per_epoch=nbatches_train,
    epochs=epochs,
    verbose=2,
    validation_data=validation_generator,
    validation_steps=nbatches_valid,
    workers=nworkers)