code: # coding=utf-8
  # Copyright 2018 The Tensor2Tensor Authors.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  """Utility to load code from an external user-supplied directory."""
  from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  
  import importlib
  import os
  import sys
  import tensorflow as tf
  
  INTERNAL_USR_DIR_PACKAGE = "t2t_usr_dir_internal"
  
  
  def import_usr_dir(usr_dir):
    """Import module at usr_dir, if provided."""
    if not usr_dir:
      return
    if usr_dir == INTERNAL_USR_DIR_PACKAGE:
      # The package has been installed with pip under this name for Cloud ML
      # Engine so just import it.
      importlib.import_module(INTERNAL_USR_DIR_PACKAGE)
      return
  
    dir_path = os.path.abspath(os.path.expanduser(usr_dir).rstrip("/"))
    containing_dir, module_name = os.path.split(dir_path)
    tf.logging.info("Importing user module %s from path %s", module_name,
                    containing_dir)
    sys.path.insert(0, containing_dir)
    importlib.import_module(module_name)
    sys.path.pop(0)
  
apis: tensorflow.logging.info