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 getAp3(self):
        ret = math.acos(((self.getLenp1() * self.getLenp1() + self.getLenp2() * self.getLenp2()) - self.getLenp3() * self.getLenp3()) / (2* self.getLenp1() * self.getLenp2()))
        return ret