in reply to arranging the csv file

Probably should use Text::CSV to parse the data, but in this case cheating isn't too bad:

use strict;
use warnings;

my %data;
map {$data{0+$_ =~ s/[ ,].*\n?//r} = $_} <DATA>;
print $data{0+$_} for qw( 10.1 100.1 25.1 103.1 );

__DATA__
100.1,A ,25, 36,56,89,45,36,56
25.1 ,B,232,565,65,56,56,48,25
103.1,C,25,5,6,9,4,5,56,889,9
10.1,D,5,6,5,8,9,8,12,23,36,6

[download]

You'd still have to account for duplicate entries and such

Replies are listed 'Best First'.
Re^2: arranging the csv file
by 2teez (Vicar) on Jul 24, 2013 at 05:59 UTC

    Hi Loops,
    Nice concept of solution, but you are "throwing" away the return values of the map function, so really, I wouldn't build my hash data like this. Moreover, this method is throwing a warnings Argument "\n" isn't numeric in addition ...
    I would rather do like so: 

    use strict;
use warnings;

my %data;
while(<DATA>){
  my ($key,$value) = split/\s+|,/=>$_,2;
  $data{$key} = $value;
}
print $_,',',$data{0+$_},$/ for qw( 10.1 100.1 25.1 103.1 );


__DATA__
100.1,A ,25, 36,56,89,45,36,56
25.1 ,B,232,565,65,56,56,48,25
103.1,C,25,5,6,9,4,5,56,889,9
10.1,D,5,6,5,8,9,8,12,23,36,6

    [download]

    If you tell me, I'll forget.
    If you show me, I'll remember.
    if you involve me, I'll understand.
    --- Author unknown to me
[reply]
[d/l]

      Marrying your and Loops' approach: 

      use strict;
use warnings;

my %data = map { /(.*?)\s*,/ => $_ } <DATA>;
print @data{ qw( 10.1 100.1 25.1 103.1 ) };

__DATA__
100.1,A ,25, 36,56,89,45,36,56
25.1 ,B,232,565,65,56,56,48,25
103.1,C,25,5,6,9,4,5,56,889,9
10.1,D,5,6,5,8,9,8,12,23,36,6

      [download]

      Question: can anyone do this as a oneliner without a named hash?

[reply]
[d/l]

        Question: can anyone do this as a oneliner without a named hash?

        Everybody can :) even you :) , do, references quick reference, hashes are curly 

        $ perl -l - 2
  print @{
          {
            map {   /(.*?)\s*,/ and $1 => $_  }
           <>
          }
        }{ qw/  10.1 100.1 25.1 103.1  / }
__END__
10.1,D,5,6,5,8,9,8,12,23,36,6
100.1,A ,25, 36,56,89,45,36,56
25.1 ,B,232,565,65,56,56,48,25
103.1,C,25,5,6,9,4,5,56,889,9

        [download]
[reply]
[d/l]

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