TB_callbacks.py

  # Create a callback for TensorBoard and put it in a list
  callbacks=[tf.keras.callbacks.TensorBoard(log_dir=model_log,
                                              histogram_freq=1,
                                              write_graph=True,
                                              write_images=False,
                                              update_freq='epoch')]

  # Create the TensorBoard writer for the confusion matrix writer
  cm_file_writer=tf.summary.create_file_writer(logdir=cm_log)

  # Add confusion matrix call back to the list of callbacks
  callbacks.append(keras.callbacks.LambdaCallback(on_epoch_end=cm_logger))