def _get_service_account_email(project_id: str,
                               service_account_name: str) -> str:
  """Retrieves the service account email id.

  Args:
    project_id: GCP project id.
    service_account_name: The service account name.

  Returns:
    service_account_email: The service account email id.
  """
  service_account_email = '{}@{}.iam.gserviceaccount.com'.format(
      service_account_name, project_id)
  return service_account_email