Here's another way... 

#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11140267
use warnings;

my $file = <<END;
702005010683593,5016683593,7020000024140
702005010640383,5016640383,7020000024150
310005010532143,5016532143,7020000034001
702005010637702,5016637702,7020000034001
702005010608274,5016608274,7020000034013
702005010608274,5016608274,7020000034013
310005010609604,5016609604,7020000034013
702005010510869,5016510869,7020000034013
702005010551513,5016551513,7020000034130
702005010551513,5016551513,7020000034130
702005010679719,5016679719,7020000034222
702005010527052,5016527052,7020000034222
702005010645458,5016645458,7020000034222
END

open my $fh, '<', \$file or die; # FIXME change for your file
my $thirty = 1; # FIXME 1 for testing, should be 30
my (%answer, %lines);
$lines{ /,(.+)/ ? $1 : die "bad data <$_>" }++ while <$fh>;
for ( keys %lines )
  {
  my ($value, $key) = split ',';
  $lines{$_} > $thirty and push @{ $answer{$key} }, $value;
  }
use Data::Dump 'dd'; dd \%answer;

[download]

In reply to Re^3: Parse file and creating hashes by tybalt89
in thread Parse file and creating hashes by PerlMonger79

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.