def robotsrulesetOfDomain(self, domain):
		'''检查domain是否在数据库中,
			否 --> (False, None)
			是 --> (True, 数据库中存储的robots.txt内容)
		'''
		exist = False
		cur = self.conn.cursor()
		# 是否存在
		cur.execute("SELECT 1 FROM Domains WHERE domain=?", (domain,))
		if cur.fetchone() :
			exist = True
		# 存在的话,结果是什么
		cur.execute("SELECT rules FROM Domains,Rulesets "
			"WHERE domain=? AND Domains.did=Rulesets.did"
			,(domain,) )
		ruleset = cur.fetchone()
		return (exist, ruleset)
def test_consumed_capacity_get_unknown_item():
    conn = boto3.client("dynamodb", region_name="us-east-1")
    conn.create_table(
        TableName="test_table",
        KeySchema=[{"AttributeName": "u", "KeyType": "HASH"}],
        AttributeDefinitions=[{"AttributeName": "u", "AttributeType": "S"}],
        BillingMode="PAY_PER_REQUEST",
    )
    response = conn.get_item(
        TableName="test_table",
        Key={"u": {"S": "does_not_exist"}},
        ReturnConsumedCapacity="TOTAL",
    )

    # Should still return ConsumedCapacity, even if it does not return an item
    response.should.have.key("ConsumedCapacity")
    response["ConsumedCapacity"].should.equal(
        {"TableName": "test_table", "CapacityUnits": 0.5}
    )