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 __extract_clusters(self):
        self.__clusters = [[] for _ in range(self.__amount_clusters)]
        for index_point in range(len(self.__data)):
            candidates = []
            for index_cluster in range(self.__amount_clusters):
                candidates.append((index_cluster, self.__rc[index_cluster][index_point]))