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 _stats_to_str(self, stats: Dict[str, str]) -> str:
        stage = f"{self._stage.upper()} " if self._stage is not None else ""
        output = [stage + "Profiler Report"]
        for action, value in stats.items():
            header = f"Profile stats for: {action}"
            if self._local_rank is not None:
                header += f" rank: {self._local_rank}"
            output.append(header)
            output.append(value)
        return os.linesep.join(output)