use strict;
use warnings;

while(<DATA>)
{

my $comment_author1;
my $comment_author2;
my $interactions;

     if( $_ =~ /(.*?),(.*?),(.*?)$/gm) {
        $comment_author1 = $1;
        $comment_author2 = $2;
        $interactions = $3;


    print "DEBUG: Looking for '$comment_author2,$comment_author1' in $_\n";
    if( $_ =~ "$comment_author2,$comment_author1") {

    print "no match\n";
    }

    else { print "$comment_author1,$comment_author2,$interactions\n";

}
}
}


__DATA__

personA,personB,10
personB,personA,190
personA,personC,23
personA,personD,43
personE,personF,10

##</code><code>##

use strict;
use warnings;

while (<DATA>) {

    my $comment_author1;
    my $comment_author2;
    my $interactions;

    if ($_ =~ /(.*?),(.*?),(.*?)$/gm) {
        $comment_author1 = $1;
        $comment_author2 = $2;
        $interactions    = $3;
        
        print "DEBUG: Looking for '$comment_author2,$comment_author1' in $_\n";
        if ($_ =~ "$comment_author2,$comment_author1") {
            print "no match\n";
        } else {
            print "$comment_author1,$comment_author2,$interactions\n";
        }
    }
}

__DATA__

personA,personB,10
personB,personA,190
personA,personC,23
personA,personD,43
personE,personF,10