Re: Different delimiter for 'collapse'

[Erik Auerswald]

Hi,

On 13.02.21 22:00, Erik Auerswald wrote:
> On 13.02.21 18:14, Eric Powell wrote:
> > Datamash is such a wonderful piece of software and I am so happy to have
> > discovered it.
> > One feature that I wish was available is to change the delimiter for the
> > collapse operation.  My data has commas in it already so I cannot
> > distinguish between those and the commas produced by collapse.  It 
> > would be
> > great if there was a command-line flag allowing the user to choose the
> > delimiter used by collapse.
>
> I second this.  It is often useful and convenient to be able to
> choose input and/or output separators.  Many programs allow to
> specify those via options.  It would be nice for datamash to
> have such options, too.

I'd say a way to change the value delimiter in comma-separated value
output is needed functionality inside of datamash, because of locale
differences.  For example, in the German locale, comma is used for
decimal numbers:

    $ echo $LC_NUMERIC
    de_DE.UTF-8
    $ printf -- '%.1f\n' 1,1 1,2 1,3 | datamash sum 1
    3,6
    $ printf -- '%.1f\n' 1,1 1,2 1,3 | datamash collapse 1
    1,1,1,2,1,3
    $ printf -- '%.1f\n' 1,1 1,2 1,3 1,1 | datamash unique 1
    1,1,1,2,1,3

To operate on decimal numbers, comma needs to be part of the input
data.  To use the unique or collapse commands with decimal numbers
with the German locale and still have useful results, a csv
delimiter different from comma is needed.  Pre and post processing
with tr is not a sufficient replacement.  Thus I'd say that it is
more than just convenient to have a way to change the value
delimiter in comma-separated value output.

Thanks,
Erik