in reply to Re^9: Iterating Through Cell Blocks with Spreadsheet::Read
in thread Iterating Through Cell Blocks with Spreadsheet::Read

Further to Anonymonk's point: 

>perl -wMstrict -le
"use Data::Dump;
 ;;
 my $sheet = { qw(F29 foo  G30 bar) };
 dd $sheet;
 ;;
 my %sheet;
 ;;
 print qq{'$sheet->{F29}'};
 print qq{'$sheet{G30}'};
"
{ F29 => "foo", G30 => "bar" }

'foo'
Use of uninitialized value $sheet{"G30"} in concatenation (.) or strin
+g at -e line 1.
''

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Do you see how the expressions  $sheet->{F29} and  $sheet{G30} access two completely different structures, one of which is empty?

... I can make no sense of the order in which it displays contents.

A hash has no internal "order" except for the pairing of each unique key with its value. Access to and listing of hash keys, values and key/value pairs is (apparently) random. (Update: Don't be mislead by the fact that the order in the dump displayed above matches the order of initialization of the hash reference example: this is entirely adventitious. The dump of a larger hash structure will show greater disorder — but again, a key always cleaves to its value.)

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Re^11: Iterating Through Cell Blocks with Spreadsheet::Read
by Hammer2001 (Novice) on Oct 08, 2013 at 23:00 UTC

    Yes, of course. Thanks for the clarification, AnomalousMonk. Now it makes. sense.

    My objective, once again, is to access F29 through F32 to K29 through K32, in a routine. I can't figure how to iterate over rows through a variable. It only works for me when hash key is explicit (i.e. $name = $sheet{"F28"};). How can I use a variable instead of "F28"?

    Thanks,

    Hammer.

[reply]
      How can I use a variable instead of "F28"?

      This essentially just goes back to toolic's original reply: make sure that  $sheet is a hash reference and that its content is what you expect; access the contents via  -> arrow notation, forming the hash keys as before with something like  $name = $sheet->{"${_}28"}; etc. (A simple concatenation like  $sheet->{$_ . '28'} would work just as well.)

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      Here's the problem restated another way. Here's a script to read Excel XLSX cell values using Spreadsheet::Read: 
      #!/usr/bin/perl -w
use warnings;
use strict;
use Spreadsheet::Read;
my $name = "";
my $strain = "";
my $initdensity = "";
my $finaldensity = "";
my $avedensity = "";
my $book;
my $sheet;
my %sheet = ();
$book = ReadData ($inbook);
my @x = qw(F G H I J K);
for my $sheet_index (1 .. $sheet_count) {
    $sheet = $book->[$sheet_index] or next;
    foreach (@x) {
       $name = $sheet{'F28'};
       $strain = $sheet{'F29'};
       $initdensity = $sheet{'F30'};
       $finaldensity = $sheet{'F31'};
       $avedensity = $sheet{'F32'};
       print "Found sheet with label: $sheet{label}\n";
       print "COL=$_ $name $strain $initdensity $finaldensity $avedens
+ity\n";
    }
}

      [download]
      I need to after reading keys F28..F32 read G28..G32 through K28..K32. How can I key it on values from array @x?

      Thanks, Hammer

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[d/l]

        I'm not at all familiar with Spreadsheet::Read (in fact, I'm not greatly familiar with spreadsheets in general), but the code you show seems close to being workable. Do this:

        • Get rid of the whole
              my %sheet = ();
          statement. In the code you show, it seems to be doing nothing more than confusing the heck out of you.
        • The  foreach (@x) { ... } loop seems OK for looping over the values of the  @x array, with the  $_ default scalar being "topicalized" to each column-name string in turn.
        • Form the cell name as has been discussed and access the cell within the  $sheet hash reference (I'm assuming this is a valid operation) using the  -> arrow operator, e.g.
              $name = $sheet->{"${_}28"};
          or perhaps
              $name = $sheet->{$_ . '28'};
        • Report results. Don't just say "it doesn't work", that's almost useless. Describe your expectations and report how the code fails to meet your expectations. Report exact warning or error messages.
        • Ponder the Basic debugging checklist.

        Good luck.

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