[galaxy-user] Question about expression in Galaxy tools

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.