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 from_mapping(
        self, mapping: t.Optional[t.Mapping[str, t.Any]] = None, **kwargs: t.Any
    ) -> bool:
        """Updates the config like :meth:`update` ignoring items with non-upper
        keys.

        .. versionadded:: 0.11
        """
        mappings: t.Dict[str, t.Any] = {}
        if mapping is not None:
            mappings.update(mapping)
        mappings.update(kwargs)
        for key, value in mappings.items():
            if key.isupper():
                self[key] = value
        return True