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 GetLogs(region, stream_name, group_name, token=None):
  """Fetches the JSON formatted log stream starting at the token."""
  get_cmd = util.AWS_PREFIX + [
      '--region', region,
      'logs', 'get-log-events',
      '--start-from-head',
      '--log-group-name', group_name,
      '--log-stream-name', stream_name,
  ]
  if token:
    get_cmd.extend(['--next-token', token])
  stdout, _, _ = vm_util.IssueCommand(get_cmd)
  return json.loads(stdout)