Beefy Boxes and Bandwidth Generously Provided by pair Networks
No such thing as a small change

Re^2: Count ID values

by kiruthika.bkite (Scribe)
on Mar 20, 2010 at 06:54 UTC ( #829771=note: print w/replies, xml ) Need Help??

in reply to Re: Count ID values
in thread Count ID values

use Data::Dumper; open FH,"DATA.txt" or die $!; my %hash; my ($a,$b); while(<FH>) { ($a,$b)=split(' '); $hash{$a}+=$b; } print Dumper \%hash;

Replies are listed 'Best First'.
Re^3: Count ID values
by GrandFather (Sage) on Mar 20, 2010 at 07:47 UTC

    Please try to provide good sample code for people new to Perl. $a and $b are special variables and are poor choices for variable names in any case. Always use strictures (use strict; use warnings;). Use the three parameter version of open and use lexical file handles. Declare variables in the smallest scope that makes sense. Try to write a self contained example that can be run. Consider:

    use strict; use warnings; my $fileName = 'data.txt'; # Create the sample data file open my $outFile, '>', $fileName or die "Failed to create $fileName: $ +!"; print $outFile <<SAMPLEDATA; Db10g029860.2 7 Db10g029860.2 1 Db10g029860.2 2 Db10g029860.2 1 Db10g029860.2 4 Db10g029860.2 2 Db10g029860.2 6 Db10g029860.2 11 Db96g938791.0 5 Db96g938791.0 9 Db96g938791.0 1 Db96g938791.0 3 Db96g938791.0 7 Db04g787390.1 6 Db04g787390.1 5 Db04g787390.1 5 Db04g787390.1 12 SAMPLEDATA close $outFile; # Process the input file open my $fileIn, '<', $fileName or die "Unable to open $fileName: $!"; my %counts; while(<$fileIn>) { chomp; my ($id, $count) = split /\s+/; next if ! $count; $counts{$id} += $count; } # Print the result for my $id (sort keys %counts) { printf "%-12s: %5d\n", $id, $counts{$id}; }


    Db04g787390.1: 28 Db10g029860.2: 34 Db96g938791.0: 25

    True laziness is hard work

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://829771]
and all is quiet...

How do I use this? | Other CB clients
Other Users?
Others chilling in the Monastery: (5)
As of 2017-02-26 15:05 GMT
Find Nodes?
    Voting Booth?
    Before electricity was invented, what was the Electric Eel called?

    Results (375 votes). Check out past polls.