Boto（Python）：检查SQS - ＆gt; SNS订阅

Question

我有一个SNS arn和一个SQS arn。我想检查两者之间是否有订阅。我现在能做到这一点的唯一方法就是强行订阅这样的订阅列表：

    result =  self.connection.get_all_subscriptions_by_topic(sns_arn)
    if (result and result['ListSubscriptionsByTopicResponse'] 
        and result['ListSubscriptionsByTopicResponse']
        and result['ListSubscriptionsByTopicResponse']['ListSubscriptionsByTopicResult']):
        subscriptions = result['ListSubscriptionsByTopicResponse']['ListSubscriptionsByTopicResult']['Subscriptions']
        for subscription in subscriptions:
            if (subscription['Protocol'] == type and subscription['Endpoint'] == sqs_arn and subscription['SubscriptionArn']):
                return subscription['SubscriptionArn']
    return None

我可以做得更好吗？