def insertDomain(self, domain, indegree=0, outdegree=0):
		'''增加一个域名'''
		cur = self.conn.cursor()
		cur.execute("INSERT INTO Domains VALUES (NULL,?,?,?)", (domain, indegree, outdegree))
		# 写入到文件中
		self.conn.commit()
def _exit_modes_beyond(self, thisMode):
        if not self.modeList: return
        while len(self.modeList) > thisMode + 1: 
            self.modeList.pop().exit()