将一段日志文本内的异常行筛选出来。

下面是一段日志文本的示例：
2021-06-22 13:23:45 [ERROR] Application failed to start
2021-06-23 08:45:20 [INFO] User logged in
2021-06-25 11:32:01 [WARNING] Disk space is running low
可以使用正则表达式匹配包含关键词的行，例如筛选出所有含有"ERROR"关键词的行：
```
import re

log = "2021-06-22 13:23:45 [ERROR] Application failed to start
2021-06-23 08:45:20 [INFO] User logged in
2021-06-25 11:32:01 [WARNING] Disk space is running low
"

for line in log.split("
"):
    if re.search("ERROR", line):
        print(line)
```