Creates a default partition.

  Args:
    client: an AdWordsClient instance.
    ad_group_id: an integer ID for an ad group.

def CreateDefaultPartition(client, ad_group_id):
  """Creates a default partition.

  Args:
    client: an AdWordsClient instance.
    ad_group_id: an integer ID for an ad group.
  """
  ad_group_criterion_service = client.GetService('AdGroupCriterionService',
                                                 version='v201809')

  operations = [{
      'operator': 'ADD',
      'operand': {
          'xsi_type': 'BiddableAdGroupCriterion',
          'adGroupId': ad_group_id,
          # Make sure that caseValue and parentCriterionId are left unspecified.
          # This makes this partition as generic as possible to use as a
          # fallback when others don't match.
          'criterion': {
              'xsi_type': 'ProductPartition',
              'partitionType': 'UNIT'
          },
          'biddingStrategyConfiguration': {
              'bids': [{
                  'xsi_type': 'CpcBid',
                  'bid': {
                      'microAmount': 500000
                  }
              }]
          }
      }
  }]

  ad_group_criterion = ad_group_criterion_service.mutate(operations)['value'][0]

  print ('Ad group criterion with ID "%d" in ad group with ID "%d" was added.'
         % (ad_group_criterion['criterion']['id'],
            ad_group_criterion['adGroupId']))