def insertRuleset(self, ruleset, domain):
		'''增加一个robots.txt规则集'''
		cur = self.conn.cursor()
		cur.execute("SELECT did FROM Domains WHERE domain=?", (domain,))
		did = cur.fetchone()[0]
		cur.execute("INSERT INTO Rulesets VALUES (NULL,?,?)",(did, ruleset))
		# 写入到文件
		self.conn.commit()
def update_snapshot_metadata_item(self, snapshot_id, id, meta_item):
        """Update metadata item for the snapshot."""
        put_body = json.dumps({'meta': meta_item})
        url = "snapshots/%s/metadata/%s" % (str(snapshot_id), str(id))
        resp, body = self.put(url, put_body)
        body = json.loads(body)
        return resp, body['meta']