Hello everyone,
 
I found regular expression could be available in the tool (filter and sort) ->Filter.  I wonder whether it could be the same in the tool (Text Manipulation) ->Compute. I have checked that the fuction "len(c4.split('_'))" would return error. So, could anyone tell me if it was possible like this?
 
The file A:
chr1    10    40    NM_1234_exon_1
chr2    50    70    NM_1234_exon_2
 
Change the file A to the file B such as:
chr1    10    40    NM_1234
chr2    50    70    NM_1234
 
 
May it is useless in the example. But the way could solve problems I met.