tsv-select: Inverse selection

[Llammissar]

I'm on fire! :D Just thought of this while I was writing #71: a way to drop columns instead of select them would probably be even clearer in many cases. Consider:
tsv-select -f 1,2,3,4,5,6,7,8,9,10,12,13,14,15,16,17,$(seq -s, 19 49) rawdata.tsv
vs.
tsv-select --inverse -f 9,18 rawdata.tsv
...or better:
tsv-select --inverse 9,18 rawdata.tsv
...because you may want to rearrange what's left:
tsv-select -v 9,18 -f 1,43,38 -r last (short option -v, like grep)
In the above example 9 and 18 are still not part of the output despite the -r last, and numbering doesn't shift for other addressing (i.e. 43 wasn't 45 before columns were removed).

Of course, it'd pair well with ranges, too, so they're not mutually exclusive:
tsv-select -v 2-9

Trying to include and exclude a field at the same time... should probably just be an error, though that could be annoying at times.

I'm not sold on the name/shortening, either. It'd make more sense for my initial thought (tsv-select -inverse -f 9,18), than the form I'd consider more usable.

[jondegenhardt]

Thanks! I'll look into this as part of field ranges.

[jondegenhardt]

Leaving this open as a separate enhancement from field ranges (Issue #71, PR #77). It's meaningfully different. For tsv-select, when variable line lengths are involved, it actually introduces new functionality, not just a more convenient way to specify fields.

[jondegenhardt]

Feature added in release 1.6.0, PR #267. This was done by adding a --e|exclude option to tsv-select. Some examples:

$   # Drop the first field, keep everything else.
$   # Equivalent to `cut -f 2- file.tsv`
$   tsv-select --exclude 1 file.tsv

$   # Drop fields 3-10, keep everything else
$   tsv-select --exclude 3-10 file.tsv

$   # Move field 2 to the start of the line, drop fields 10-15
$   tsv-select -f 2 -e 10-15 file.tsv

$   # Move field 2 to the end, dropping fields 10-15
$   tsv-select -f 2 --rest first -e 10-15 file.tsv

For more info see PR #267 and the tsv-select reference doc.