code: def environment_exists(self, env_name):
          
          response = self.ebs.describe_environments(application_name=self.app_name, environment_names=[env_name],
                                                    include_deleted=False)
          return len(response['DescribeEnvironmentsResponse']['DescribeEnvironmentsResult']['Environments']) > 0 \
                 and response['DescribeEnvironmentsResponse']['DescribeEnvironmentsResult']['Environments'][0][
                         'Status'] != 'Terminated'
docs: Returns whether or not the given environment exists