Perl: Dump data from a hash into excel - arrays

Question

I have a hash with key and Values(array). I want to dump them to a spreadsheet, but having difficulty in arranging them .
%hash
key1 -> foo bar
key2-> john adam gill
key3-> apple banana mango orange
Code:
use strict;
use warnings;
use Excel::Writer::XLSX;
my $pattern = "BEGIN_";
my $format;
my #keys = qw(key1 key2 key3);
foreach my $key(#keys){
open my $fh, "<","filename.txt" or die $!;
while ( <$fh> ) {
if (/$pattern/) {
push(#matching_lines, $_);
}
}
$hash{$key} = [#matching_lines] ;
for (#matching_lines) { $_ = undef } ; #Emptying the array contents,to reuse it for for all the other keys
}
my $workbook = Excel::Writer::XLSX->new( 'c:\TEMP\filename.xlsx' );
if (not defined $workbook)
{
die "Failed to create spreadsheet: $!";
}
my $worksheet = $workbook->add_worksheet();
# Add and define a format
$format = $workbook->add_format();
$format->set_bg_color( 'yellow' );
my $row = 1;
my $col = 0;
foreach my $k (keys %hash)
{
$worksheet->write($row, $col, $k, $format); # title
$worksheet->write_col($row+1, $col, $hash{$k}); #value
$col++;
}
$workbook->close() or die "Error closing file: $!";
Current Output
Desired Output

Answer 1

Edit: Now you've actually updated your program to clarify that the problem is how you're reading your data, the below is moot. But it does illustrate an alternative approach.
OK, the core problem here is what you're trying to do is 'flip' a hash. You're printing row by row, but your hash is organised in columns.
Using comma sep as a quick proxy for printing actual excel:
#!/usr/bin/env perl
use strict;
use warnings;
use Data::Dumper;
#initialise
my %hash = (
key1 => [qw ( foo bar )],
key2 => [qw ( john adam gill )],
key3 => [qw ( apple banana mango orange )],
);
#print for debug
print Dumper \%hash;
#get header row. Sort it, because hashes are unordered.
#could instead:
#my #keys = qw ( key1 key2 key3 );
my #keys = sort keys %hash;
#print header row
print join ",", #keys, "\n";
#iterate until every element of the hash is gone
while ( map { #{ $hash{$_} } } #keys ) {
#cycle the keys, shifting a value of the top of each array.
#replace any undefined values with ''.
print shift( #{ $hash{$_} } ) // '', "," for #keys;
print "\n";
}
This prints:
key1,key2,key3,
foo,john,apple,
bar,adam,banana,
,gill,mango,
,,orange,
Which if you load it as csv into Excel, should give your desired result. I'm pretty sure you could use a similar 'write row' with the module.
So this actually seems to do what you want:
#!/usr/env/perl
use strict;
use warnings;
use Excel::Writer::XLSX;
#initialise
my %hash = (
key1 => [qw ( foo bar )],
key2 => [qw ( john adam gill )],
key3 => [qw ( apple banana mango orange )],
);
my $workbook = Excel::Writer::XLSX->new('c:\TEMP\filename.xlsx');
if ( not defined $workbook ) {
die "Failed to create spreadsheet: $!";
}
my $worksheet = $workbook->add_worksheet();
# Add and define a format
my $format = $workbook->add_format();
$format->set_bg_color('yellow');
my #keys = sort keys %hash;
my $row = 0;
$worksheet->write_row( $row++, 0, \#keys, $format );
while ( map { #{ $hash{$_} } } #keys ) {
my $col = 0;
$worksheet->write( $row, $col++, shift( #{ $hash{$_} } ) // '' )
for #keys;
$row++;
}
$workbook->close() or die "Error closing file: $!";

Answer 2

You're not correctly emptying your #matching_lines array. This line:
for (#matching_lines) { $_ = undef }
Sets the array values to undef, but does not remove them.
For example, if #matching_lines was ('foo', 'bar'), now it becomes (undef, undef). When you add baz and qux to it later, it becomes (undef, undef, 'baz', 'qux'). These undefs become blank cells when you add them to the worksheet.
To correctly empty the array, use:
#matching_lines = ();