def close(self):
		'''关闭与数据库的连接'''
		if VERBOSE:
			print 'Database connection CLOSE.'
		self.conn.close()
def __initialize_kmeans(self):
        initial_centers = kmeans_plusplus_initializer(self.__sample, self.__amount).initialize()
        kmeans_instance = kmeans(self.__sample, initial_centers, ccore = True)
        kmeans_instance.process()