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 ProcessCommandLineArgs(parser, args):
  # TODO(ariblue): Delete this flag entirely at some future data, when the
  # existence of such a flag has been long forgotten.
  if args.output_file:
    parser.error('This flag is deprecated. Please use --output-dir instead.')

  try:
    os.makedirs(args.output_dir)
  except OSError:
    # Do nothing if the output directory already exists. Existing files will
    # get overwritten.
    pass

  args.output_dir = os.path.expanduser(args.output_dir)