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Re: Hashes of Hashes of Arrays? Is it possible?

by liverpole (Monsignor)
on Sep 08, 2011 at 18:49 UTC ( #924906=note: print w/ replies, xml ) Need Help??


in reply to Hashes of Hashes of Arrays? Is it possible?

Hi capriguy84,

Looks to me like you've got a simple typo ... first you called the data structure %HOH, then later you referred to it as %HoH. One other typo in your code is the extra quotation mark (or "double quotes" character) on this line:

pal => "[ "george", "jane", "elroy" ],

Fixing those 2 things, giving explicit values for $key and $value, and using Data::Dumper to check the results:

use strict; use warnings; use Data::Dumper; my %HoH = ( flintstones => { lead => "fred", pal => [ "george", "jane", "elroy" ], }, jetsons => { lead => "george", wife => [ "george", "jane", "elroy" ], boy => [ "george", "jane", "elroy" ], }, simpsons => { lead => "homer", wife => [ "george", "jane", "elroy" ], kid => [ "george", "jane", "elroy" ], }, ); my $key = 'flintstones'; my $value = 'Wilma'; printf "Before: %s\n", Dumper(\%HoH); $HoH{$key}{"name"} = $value; printf " After: %s\n", Dumper(\%HoH); __END__ Output (Note that 'Wilma' was successfully added): Before: $VAR1 = { 'simpsons' => { 'kid' => [ 'george', 'jane', 'elroy' ], 'lead' => 'homer', 'wife' => [ 'george', 'jane', 'elroy' ] }, 'jetsons' => { 'lead' => 'george', 'wife' => [ 'george', 'jane', 'elroy' ], 'boy' => [ 'george', 'jane', 'elroy' ] }, 'flintstones' => { 'lead' => 'fred', 'pal' => [ 'george', 'jane', 'elroy' ] } }; After: $VAR1 = { 'simpsons' => { 'kid' => [ 'george', 'jane', 'elroy' ], 'lead' => 'homer', 'wife' => [ 'george', 'jane', 'elroy' ] }, 'jetsons' => { 'lead' => 'george', 'wife' => [ 'george', 'jane', 'elroy' ], 'boy' => [ 'george', 'jane', 'elroy' ] }, 'flintstones' => { 'lead' => 'fred', 'name' => 'Wilma', 'pal' => [ 'george', 'jane', 'elroy' ] } };

s''(q.S:$/9=(T1';s;(..)(..);$..=substr+crypt($1,$2),2,3;eg;print$..$/


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Re^2: Hashes of Hashes of Arrays? Is it possible?
by capriguy84 (Novice) on Sep 08, 2011 at 19:07 UTC
    Thanks for your reply. I am reading a CSV file(below) and creating a temporary complex hash structure as described to perform some operations. As you can see my $key is the time which should be only one per second and plug the data as hash/array.
    NAME,06/01/2011,09:30:00,16.76,756,Q,00 NAME,06/01/2011,09:30:00,16.76,300,Q,00 NAME,06/01/2011,09:30:00,16.76,100,Q,00 NAME,06/01/2011,09:30:01,16.76,100,Q,00 NAME,06/01/2011,09:30:01,16.76,200,Z,00 NAME,06/01/2011,09:30:02,16.77,200,X,00 NAME,06/01/2011,09:30:02,16.77,200,X,00

    Open 100k line CSV file and read using Text_CSV. I have to undef the hashes before jumping to next second.
    my $csv = Text::CSV_XS->new(); open (FILE, "<", "$tickdir/$file") or die "Can't open CSV File:$! +\n"; while (<FILE>) { $csv->parse($_); my @columns = $csv->fields(); my $key = str2time($columns[1].' '.$columns[2]); my (@prices, @volumes) = (); my %HOH = (); $HOH{$key}{"name"} = $columns[0]; push(@{$HOH{$key}{"price"}}, $columns[3]); push(@{$HOH{$key}{"volumes"}}, $columns[4]); print Dumper(\%HOH); } close FILE;
    OUTPUT: As you can see the key values are same.
    $VAR1 = { '1306935005' => { 'volumes' => [ '200' ], 'name' => 'NAME', 'price' => [ '16.76' ] } }; $VAR1 = { '1306935005' => { 'volumes' => [ '400' ], 'name' => 'NAME', 'price' => [ '16.76' ] } };
      You are overwriting your hash every time through the while loop. Move the declaration of the hash outside of the loop:
      my $csv = Text::CSV_XS->new(); open (FILE, "<", "$tickdir/$file") or die "Can't open CSV File:$! +\n"; my %HOH; while (<FILE>) { $csv->parse($_); my @columns = $csv->fields(); my $key = str2time($columns[1].' '.$columns[2]); my (@prices, @volumes) = (); $HOH{$key}{"name"} = $columns[0]; push(@{$HOH{$key}{"price"}}, $columns[3]); push(@{$HOH{$key}{"volumes"}}, $columns[4]); print Dumper(\%HOH); } close FILE;
        ahh..That fixed it. Thank you very much. One quick question, how do I avoid having to save the huge dataset in memory by processing and printing the results on fly? I would like to undef the HASH at after each second in time i.e create a loop for each key and undef my %HOH. Any ideas how/where I can add the control statement for $key?
        Jim, Is there a Perl specific control break? Or should I just permutate various loop control statements like unless, continue etc.?

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