Hi, thanks for the reply. Sorry I didn't provide examples of the code but the powers that be won't let me you see (they try to shut me down on MTV.. heh, sorry). Your example helped a lot though, and I have most of it done. Just two more questions with regards to the data structures, could you let me know how close these are:

name = thingy['albums'][0]['title']
$name = $thingy{albums}[0]{title}
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Should both return 'Foxtrot' (without the quotes), correct?

And as for populating the structures, could I do something such as the following:

thingy['artistName'][0]['year'] = 1987
or
thingy{'artistName}[0]{'year'} = 1987
[download]

And if I did it this way, how would I go about populating multiple entries in the album field, would I have to use a counter, or is there some other way? Thanks again.

Your first snippet is close, but thingy is a an array/list, not a hash/dictionary, so you need to index the very first item in that array/list, which is a hash/dictionary:

name = thingy[0]['albums'][0]['title']

my $name = $thingy->[0]{albums}[0]{title};
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For your second snippet, you will need to loop through each hash/dictionary that is contained inside the 'album' array/list:

for a in thingy[0]['albums'] : a['year'] = 1999

$_->{year} = 1999 for @{$thingy->[0]->{albums}};
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As you can see, you don't need a counter, you only need to process each element at a time. Perl and Python are both good about giving the coder 'ease of iteration'. ;)

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

Okay, I've got another fine Python question for you wise Perlmonks (well, know thy enemy, right? ;-). Say I want data such as:

genesis = { "Foxtrot":({"instrumental":"Okay"}, {"vocals":"Good"}), "D
+uke":({"vocals":"Better"}) }
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How would I go about initially populating the dictionary? Say, as if I was reading from a database and looping over it. There isn't an insert or append operator for dictionaries, and I can't seem to just go: genesis["Foxtrot"]["instrumental"] = "Okay" Any ideas? Thanks.

That's right, what you have is illegal syntax in either language. You are trying to access a HoH (hash of hashes) instead of what you really have, a LoH (list of hashes). You simply are missing the array index:

genesis['Foxtrot'][0]['instrumental'] = 'excellent'

$gensis->{Foxtrot}[0]{instrumental} = 'excellent';
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Now then, as for populating these datastructures from a database ... well, i can't help you much with Python. You'll have to read the docs, but i can say that Perl's DBI has methods that will form these datastructures for you, methods such as:
• selectall_arrayref
• selectall_hashref
• fetchrow_arrayref
• fetchrow_hashref
and more. I usually only use selectall_arrayref, but sometimes i need the lookup power of hashes. You have to ensure that all of your data has unique id's in order for hashes to work safely (without clobbering existing keys). Recently i decided to roll my own:

# takes prepared statement handle and returns LoH
sub db2tmpl {
    my ($sth) = @_;
    $sth->execute;
    my $fields = $sth->{NAME};
    my $rows   = $sth->fetchall_arrayref;
    my @loh;
    for my $row (@$rows) {
        my %hash;
        @hash{@$fields} = @$row;
        push @loh, {%hash};
    }
    return \@loh;
}
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This is very useful with HTML::Template, though i can't help but feel i am re-inventing a wheel. At any rate, i wish you the best of luck. :)

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

Thanks for reply. Sorry for the confusion, what I meant by populating the datastructure was the actual looping over and adding entries (this seems pretty straightforward now given your other post). I don't have any problems with reading the data from the database, the docs were decent in both languages for that :).

Thanks for all the help, I think I've got it now :)