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 split_container(container, iter):
	root = Tree(container)
	if iter != 0:
		sr = random_split(container)
		if sr!=None:
			root.lchild = split_container(sr[0], iter-1)
			root.rchild = split_container(sr[1], iter-1)
	return root