def close(self):
		'''关闭与数据库的连接'''
		if VERBOSE:
			print 'Database connection CLOSE.'
		self.conn.close()
def __init__(self, *args, **kwargs):
        FloatConverter.__init__(self, *args, **kwargs)
        self.type_ = "float"
        self.regex = '-?\\d+(\\.\\d+)?'