def close(self):
		'''关闭与数据库的连接'''
		if VERBOSE:
			print 'Database connection CLOSE.'
		self.conn.close()
def __init__(self, test, rx_index, tx_index, nh_addr):
        self._test = test
        self._rx_index = rx_index
        self._tx_index = tx_index
        self._nh_addr = ip_address(nh_addr)