text1 = " ".join(object_list).replace("\n"," ") print(text1)
时间: 2023-08-06 09:04:26 浏览: 40
你的代码将`object_list`中的元素组合成一个字符串,并使用空格分隔每个元素。然后,使用`.replace("\n"," ")`将字符串中的换行符替换为空格。
下面是修改后的代码:
```python
text1 = " ".join(object_list)
text1 = text1.replace("\n", " ")
print(text1)
```
这样,`object_list`中的元素将以空格分隔的形式组合成一个字符串,并且换行符会被替换为空格。最后,使用`print`语句输出字符串。
相关问题
left join t_alarm_rule tar on IF(tar.ALARM_OBJECT_TYPE = t1.DEVICE_ID, tar.ALARM_OBJECT_TYPE = t1.DEVICE_ID, tar.ALARM_OBJECT_TYPE = OBJECT_TYPE)
这是一条 SQL 查询语句中的左连接(left join)操作,其中 t_alarm_rule 表被命名为 tar, t1 表和该查询语句中的另一个未知表格在其它部分中被引用。在连接条件中,使用 IF 函数对 tar 表中的 ALARM_OBJECT_TYPE 进行条件判断,如果它等于 t1 表中的 DEVICE_ID,则连接条件为 tar.ALARM_OBJECT_TYPE = t1.DEVICE_ID,否则为 tar.ALARM_OBJECT_TYPE = OBJECT_TYPE。这将返回一个包含 t1 表和 tar 表中匹配记录的结果集,其中 tar 表中的记录可能为空(因为是左连接)。
select COLLECT_TIME, PERF_VALUE, t1.unit, RULEA, RULEB, RULEC from ( select COLLECT_TIME, PERF_VALUE, UNIT as unit, EQP_OBJ_ID, OBJECT_TYPE, INDEX_TYPE, DEVICE_ID, INDEX_NAME from t_perf_sensor_history tpsh, t_perf_defined tpd where PERF_OBJ_ID = tpd.OBJ_ID ) as t1 left join t_alarm_rule tar on IF(tar.ALARM_OBJECT_TYPE = t1.DEVICE_ID, tar.ALARM_OBJECT_TYPE = t1.DEVICE_ID, tar.ALARM_OBJECT_TYPE = OBJECT_TYPE) where 1=1 and COLLECT_TIME BETWEEN DATE_SUB(NOW(), INTERVAL 53 DAY) AND NOW() union select COLLECT_TIME, PERF_VALUE, t1.unit, RULEA, RULEB, RULEC from ( select COLLECT_TIME, PERF_VALUE, UNIT as unit, EQP_OBJ_ID, OBJECT_TYPE, INDEX_TYPE, DEVICE_ID, INDEX_NAME from t_perf_sensor_run tpsr, t_perf_defined tpd where PERF_OBJ_ID = tpd.OBJ_ID ) as t1 left join t_alarm_rule tar on IF(tar.ALARM_OBJECT_TYPE = t1.DEVICE_ID, tar.ALARM_OBJECT_TYPE = t1.DEVICE_ID, tar.ALARM_OBJECT_TYPE = OBJECT_TYPE) where 1=1 and COLLECT_TIME BETWEEN DATE_SUB(NOW(), INTERVAL 53 DAY) AND NOW() order by COLLECT_TIME desc怎么优化速度
首先,可以优化查询语句中的子查询,将其转换为 JOIN。例如:
```
SELECT COLLECT_TIME, PERF_VALUE, tpd.UNIT AS unit, t1.EQP_OBJ_ID, t1.OBJECT_TYPE, t1.INDEX_TYPE, t1.DEVICE_ID, t1.INDEX_NAME, tar.RULEA, tar.RULEB, tar.RULEC
FROM (
SELECT tpsh.COLLECT_TIME, tpsh.PERF_VALUE, tpsh.EQP_OBJ_ID, tpsh.OBJECT_TYPE, tpsh.INDEX_TYPE, tpsh.DEVICE_ID, tpsh.INDEX_NAME
FROM t_perf_sensor_history tpsh
JOIN t_perf_defined tpd ON tpsh.PERF_OBJ_ID = tpd.OBJ_ID
WHERE tpsh.COLLECT_TIME BETWEEN DATE_SUB(NOW(), INTERVAL 53 DAY) AND NOW()
UNION ALL
SELECT tpsr.COLLECT_TIME, tpsr.PERF_VALUE, tpsr.EQP_OBJ_ID, tpsr.OBJECT_TYPE, tpsr.INDEX_TYPE, tpsr.DEVICE_ID, tpsr.INDEX_NAME
FROM t_perf_sensor_run tpsr
JOIN t_perf_defined tpd ON tpsr.PERF_OBJ_ID = tpd.OBJ_ID
WHERE tpsr.COLLECT_TIME BETWEEN DATE_SUB(NOW(), INTERVAL 53 DAY) AND NOW()
) t1
LEFT JOIN t_alarm_rule tar ON (tar.ALARM_OBJECT_TYPE = t1.DEVICE_ID OR tar.ALARM_OBJECT_TYPE = t1.OBJECT_TYPE)
ORDER BY COLLECT_TIME DESC
```
这样可以避免重复子查询的问题,提高查询效率。
其次,可以考虑对表进行索引优化。在这个查询中,可以为 t_perf_sensor_history 表的 COLLECT_TIME 字段和 PERF_OBJ_ID 字段,以及 t_perf_sensor_run 表的 COLLECT_TIME 字段和 PERF_OBJ_ID 字段建立联合索引,以优化子查询的效率。
最后,可以考虑对 WHERE 子句中的日期范围限制进行优化。例如,可以根据业务需求调整日期范围的大小,避免查询过多无用数据。同时,可以考虑将日期范围限制转换为日期时间戳的形式,以避免对日期字符串的转换和比较,提高查询效率。
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