Delete lines from CSV where column cell value is null

joshmcbride95 has asked for the wisdom of the Perl Monks concerning the following question:

hi guys, I have a script that opens a csv containing 50 columns, and splits it into two files, the first containing 30 columns, and the second containing 20 columns. I now need to re-open these files and delete rows where the column 0 is null and column 4 is null.

open my $in,  '<:encoding(utf8)', $filepath_in or die;
open my $courier_out_temp, '>:encoding(utf8)', $filepath_out_temp_cour
+ier or die;

while ( my $row = $csv->getline( $in ) ) {
    
    splice @$row, 0, 38;
 
    my $status = $csv->combine(@$row);
    if ($status) {
       print $courier_out_temp $csv->string(), "\n";
    }
    
}
[download]

I have this script, which works fine, and have tried various approaches to delete the records. Can anyone help?

Comment on Delete lines from CSV where column cell value is null Download Code

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Re: Delete lines from CSV where column cell value is null by choroba (Cardinal) on Nov 24, 2018 at 22:59 UTC
You can use a filter: `#!/usr/bin/perl use strict; use warnings; use Text::CSV_XS qw{ csv }; csv(in => shift, eol => "\n", filter => {1 => sub { length }, 5 => sub { length }});` [download] It will only keep the lines where columns 1 and 5 (1-based) have a non-zero length. Tested on: Read more... (379 Bytes) ($q=q:Sq=~/;[c](.)(.)/;chr(-\|\|-\|5+lengthSq)`"S\|oS2"`map{chr \|+ord }map{substrSq`S_+\|`\|}3E\|-\|`7**2-3:)=~y+S\|`+$1,++print+eval$q,q,a, [download]	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re: Delete lines from CSV where column cell value is null
by choroba (Cardinal) on Nov 24, 2018 at 22:59 UTC

#!/usr/bin/perl
use strict;
use warnings;

use Text::CSV_XS qw{ csv };

csv(in     => shift,
    eol    => "\n",
    filter => {1 => sub { length },
               5 => sub { length }});
[download]

It will only keep the lines where columns 1 and 5 (1-based) have a non-zero length.

Tested on: