text: # Copyright 2019 The TensorFlow Authors. All Rights Reserved.
  #
  # 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.
  # ==============================================================================
  """Initializes TPU system for TF 2.0."""
  
  import tensorflow as tf
  
  
  def tpu_initialize(tpu_address):
    """Initializes TPU for TF 2.0 training.
  
    Args:
      tpu_address: string, bns address of master TPU worker.
  
    Returns:
      A TPUClusterResolver.
    """
    cluster_resolver = tf.distribute.cluster_resolver.TPUClusterResolver(
        tpu=tpu_address)
    if tpu_address not in ('', 'local'):
      tf.config.experimental_connect_to_cluster(cluster_resolver)
    tf.tpu.experimental.initialize_tpu_system(cluster_resolver)
    return cluster_resolver
  