old_contents: #!/usr/bin/env python
  
  # Copyright (C) 2013 Google Inc.
  #
  # 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.
  
  # [START all]
  
  """Command-line sample application for listing all objects in a bucket using
  the Cloud Storage API.
  
  This sample is used on this page:
  
      https://cloud.google.com/storage/docs/json_api/v1/json-api-python-samples
  
  For more information, see the README.md under /storage.
  """
  
  import argparse
  import json
  
  from googleapiclient import discovery
  from oauth2client.client import GoogleCredentials
  
  
  def main(bucket):
      # [START list_bucket]
      # Get the application default credentials. When running locally, these are
      # available after running `gcloud init`. When running on compute
      # engine, these are available from the environment.
      credentials = GoogleCredentials.get_application_default()
  
      # Construct the service object for interacting with the Cloud Storage API -
      # the 'storage' service, at version 'v1'.
      # You can browse other available api services and versions here:
      #     https://developers.google.com/api-client-library/python/apis/
      service = discovery.build('storage', 'v1', credentials=credentials)
  
      # Make a request to buckets.get to retrieve a list of objects in the
      # specified bucket.
      req = service.buckets().get(bucket=bucket)
      resp = req.execute()
      print(json.dumps(resp, indent=2))
      # [END list_bucket]
  
      # Create a request to objects.list to retrieve a list of objects.
      fields_to_return = \
          'nextPageToken,items(name,size,contentType,metadata(my-key))'
      req = service.objects().list(bucket=bucket, fields=fields_to_return)
  
      # If you have too many items to list in one request, list_next() will
      # automatically handle paging with the pageToken.
      while req:
          resp = req.execute()
          print(json.dumps(resp, indent=2))
          req = service.objects().list_next(req, resp)
  
  
  if __name__ == '__main__':
      parser = argparse.ArgumentParser(
          description=__doc__,
          formatter_class=argparse.RawDescriptionHelpFormatter)
      parser.add_argument('bucket', help='Your Cloud Storage bucket.')
  
      args = parser.parse_args()
  
      main(args.bucket)
  # [END all]
  
new_contents: #!/usr/bin/env python
  
  # Copyright (C) 2013 Google Inc.
  #
  # 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.
  """Command-line sample application for listing all objects in a bucket using
  the Cloud Storage API.
  
  This sample is used on this page:
  
      https://cloud.google.com/storage/docs/json_api/v1/json-api-python-samples
  
  For more information, see the README.md under /storage.
  """
  
  import argparse
  import json
  
  from googleapiclient import discovery
  
  from oauth2client.client import GoogleCredentials
  
  
  def create_service():
      """Creates the service object for calling the Cloud Storage API."""
      # Get the application default credentials. When running locally, these are
      # available after running `gcloud init`. When running on compute
      # engine, these are available from the environment.
      credentials = GoogleCredentials.get_application_default()
  
      # Construct the service object for interacting with the Cloud Storage API -
      # the 'storage' service, at version 'v1'.
      # You can browse other available api services and versions here:
      #     https://developers.google.com/api-client-library/python/apis/
      return discovery.build('storage', 'v1', credentials=credentials)
  
  
  def get_bucket_metadata(bucket):
      """Retrieves metadata about the given bucket."""
      service = create_service()
  
      # Make a request to buckets.get to retrieve a list of objects in the
      # specified bucket.
      req = service.buckets().get(bucket=bucket)
      return req.execute()
  
  
  def list_bucket(bucket):
      """Returns a list of metadata of the objects within the given bucket."""
      service = create_service()
  
      # Create a request to objects.list to retrieve a list of objects.
      fields_to_return = \
          'nextPageToken,items(name,size,contentType,metadata(my-key))'
      req = service.objects().list(bucket=bucket, fields=fields_to_return)
  
      all_objects = []
      # If you have too many items to list in one request, list_next() will
      # automatically handle paging with the pageToken.
      while req:
          resp = req.execute()
          all_objects.extend(resp.get('items', []))
          req = service.objects().list_next(req, resp)
      return all_objects
  
  
  def main(bucket):
      print(json.dumps(get_bucket_metadata(bucket), indent=2))
      print(json.dumps(list_bucket(bucket), indent=2))
  
  
  if __name__ == '__main__':
      parser = argparse.ArgumentParser(
          description=__doc__,
          formatter_class=argparse.RawDescriptionHelpFormatter)
      parser.add_argument('bucket', help='Your Cloud Storage bucket.')
  
      args = parser.parse_args()
  
      main(args.bucket)
  
subject: Refactor storage sample for better code-inclusion