Tigor:

You were pretty close with your code. The problem is how you built your key.

In your desired output, you show that you want to use the first column as the key, but you used:

my $key = join(' ', splice(@fields, 0, 2));
                    \_______ ____________/
          \                 v
           \               (1)
            \___ __________________________/
                v
               (2)
[download]

That explicitly (1) takes the first two columns out of @fields (two columns starting at zero), and then (2) joins them together with a space to build $key.

Since you wanted only the first column as the key, you could have used:

which would have taken just the first column and used it as the key. However, there are other ways. The shift operator, for example, will remove the first item from a list, so you could get the same result like this:

However the method I would use is the same one proposed by poj, which is to do it when you split the line into fields:

Here, when split creates a list of values, it puts the first one in $key and the rest of them in @fields. Note: when you do it like this, the first array on the left side will consume *all* the values. So doing something like the following:

leaves the last value undefined. You'd get $key='Apple', @fields=[40, 45, 50, 54], and $apr=undef for the first line of data.

Update: I bumbled Tigor's name. Thanks, chirooba! ;^)

...roboticus

When your only tool is a hammer, all problems look like your thumb.

Looks like the key is column 1 only.

while (<DATA>) {
    my ($key,@fields) = split;
    $data{$key} = \@fields;
}
[download]

Hello Tigor,

I was under the impression that you want also to calculate the average or the values e.g. (see bellow):

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

use IO::All;
use Data::Dumper;
use List::Util qw(sum);

sub mean {
    return sum(@_)/@_;
}

my @lines = io('in.txt')->chomp->slurp;
splice @lines, 0, 1; # remove first line

my %hash;
foreach my $line (@lines) {
    $line =~ s/^\s+//;
    my @elements = split /\s+/, $line;
    my $reference = splice @elements, 0, 1;
    $hash{$reference} = mean(@elements);
}
print Dumper \%hash;

__END__

$ perl test.pl
$VAR1 = {
          'Pineapple' => '25',
          'Apple' => '47.25',
          'orange' => '22.5'
        };
[download]

If not you can simply do this (see bellow):

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

use IO::All;
use Data::Dumper;

my @lines = io('in.txt')->chomp->slurp;
splice @lines, 0, 1; # remove first line

my %hash;
foreach my $line (@lines) {
    $line =~ s/^\s+//;
    my @elements = split /\s+/, $line;
    $hash{splice @elements, 0, 1} = \@elements;
}
print Dumper \%hash;

__END__

$ perl test.pl
$VAR1 = {
          'Pineapple' => [
                           '10',
                           '20',
                           '30',
                           '40'
                         ],
          'orange' => [
                        '12',
                        '25',
                        '24',
                        '29'
                      ],
          'Apple' => [
                       '40',
                       '45',
                       '50',
                       '54'
                     ]
        };
[download]

I hope this helps, BR.

Two nits: Why use splice @lines, 0, 1; instead of shift, and why use split /\s+/ when split ' ' does the same thing but discards leading whitespace? splice @elements, 0, 1; discards the first element regardless of what it contains, even if the file format changes and there is no more whitespace at the front of the lines.

Hello haukex,

Yes you are right, I was not thinking clearly on that day and I made the code more complex without any reason :).

Thanks for pointing out minor possible improvements.

BR / Thanos

Seeking for Perl wisdom...on the process of learning...not there...yet!

Hi thanos1983,The code which was shared by you absolutely brilliant piece of code and helped me a lot but what if there is a bit change in the text file mentioned below input file.I have tried but i am getting the output as {''=>[],Apple =>[A,40,45,50,54]} with first line empty and actual data is starting after the comma seperation & A in displaying in an array actually it has to dispay as {Apple-A =>[40,45,50,54]} .Any help is appreciated

Below is the code used to achieve the output

use strict;
use warnings;

use IO::All;
use Data::Dumper;
my @elements =();
my @lines = io('test_scores.txt')->chomp->slurp;
splice @lines, 0, 1; # remove first line

my %hash;

foreach my $line (@lines) {
    $line =~ s/^\s+//;
    my @elements = split /\s+/, $line;
    $hash{splice @elements, 0, 1} = \@elements;    
}
print Dumper \%hash;
[download]

below is the Input file

fruit    Jan feb mar apr
Apple A  40  45  50  54
orange O 12  25  24  29
Pineapple P 10 20 30 40
[download]

output should be as below

{Apple-A =>[40,45,50,54]}

Make the key by joining the first 2 fields. see splice and join

foreach my $line (@lines) {
    $line =~ s/^\s+//;
    my @elements = split /\s+/, $line;
    my $key = join '-',splice @elements, 0, 2; # 2 col key 
    $hash{$key} = \@elements if length($key) > 0; # no blank keys   
}
[download]

poj

The code you posted in the root node works for this case...

duplicate node, please delete

my $key = join(' ', splice(@fields, 0, 2));
                    \_______ ____________/
          \                 v
           \               (1)
            \___ __________________________/
                v
               (2)
[download]