【问题】
Ok, so I'm trying to read a log file and parse useful data out of it.
it looks kind of like
webcat_service,1.0,50
webcat_service,1.5,30
webcat_service,2.5,10
webcat_service,4.0,5
webroot_service,10.0,50
webroot_service,15.0,20
webroot_service,20.0,10
webroot_service,30.0,5
at this point.
Now, what I want is to split that off into
webcat_service_1.0,50
webcat_service_1.5,30
webcat_service_2.5,10
webcat_service_4.0,5
webcat_service_avg, $FOO
webroot_service,10.0,50
webroot_service,15.0,20
webroot_service,20.0,10
webroot_service,30.0,5
webroot_service_avg, $BAR
I can do the easy part (putting the values together, running the function that spits back an average, and puts it in the right place), but I can't figure out how to write a loop that takes input until a variable is different, then put that into the check ("look at webcat until you see something else, then run this function again with webroot")
【回答】
在已经分组的数据间插入汇总值，通常的做法是依次读入本组数据，直到数据发生变化，然后将本组数据和汇总值追加到新文件中，再读入下一组数据。可以用硬编码实现上述算法，但过程有些麻烦，这种情况下可以考虑用SPL，具体代码如下：
| A | B | |
| 1 | =file("E: \\webdata.log").cursor@c() | =file("e:\\result.txt") |
| 2 | for A1;_1 | =B1.export@ac(A2) |
| 3 | =A2._1+"_avg,"+string(A2.avg(_2))+"\r\n" | |
| 4 | =B1.write@a(B3) |
A1：读取逗号分隔的webdata.log中的内容，结果返回游标。
A2-B4：循环读取A1第一列内容，并进行计算。
A2：每次从A1读取部分记录至第一列数据有变化(即先读取第一列为webcat_service的数据，再读取第一列为webroot_service的数据)。
B2：先将A2追加导入到result.txt
B3：增加一行数据，并计算A2第2列的平均值。
B4：将增加的行追加写入result.txt。