Anonymous Monk has found why the diamond operator does not work.

DB_File or any other BTree storage likely is installed already with your Perl, like DBM_File or SDBM_File, and they can be used to conveniently rearrange the data and adress it by a common key.

Have you considered concatenating all your CSV files into a single file? If you then sort that single file by the columns you want to use as keys, all your calculations become much simpler as you only have one set of variables that you purge whenever your key changes.

I will mention Yes, even you can use CPAN, but it's only for future reference as DBD::SQLite will need a C compiler, so you can't completely paste it into your script.

In reply to Re^3: agregating columns in several csv files by Corion
in thread agregating columns in several csv files by Utilitarian

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.