in ncf.py [0:0]
def _load_training_data(base_dir):
""" load training data """
df_train = np.load(os.path.join(base_dir, 'train.npy'))
user_train, item_train, y_train = np.split(np.transpose(df_train).flatten(), 3)
return user_train, item_train, y_train