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 dec_c(self, ind):
        r, c = self.row_col(ind)
        c -= 1
        if c < 0:
            c = self.nc - 1
        if r == (self.nr - 1) and c == (self.nc - 1):
            c = self.nc - 2
        return self.indx(r, c)