head

C<Data::Reshapers::ToWideFormat> package module has functions that convert data structures coercible to full-arrays
into corresponding wide formats. The central data structure is a positional (list or array) of hashes.



unit module Data::Reshapers::ToWideFormat;

#===========================================================
our proto auto-aggregator(|) is export {*}

multi auto-aggregator(Num @vec ) { @vec.sum }

multi auto-aggregator(Str @vec) { @vec.join(', ') }

multi auto-aggregator($vec) {
    my Num @arr;
    try { @arr = $vec }
    if $! { $vec.join('; ') }
    else { auto-aggregator(@arr) }
}


#===========================================================
our proto ToWideFormat(|) is export {*}

#-----------------------------------------------------------
#| To long form conversion for arrays of hashes.
multi ToWideFormat(@tbl,
                   :$identifierColName = Whatever,
                   Str:D :$variablesFrom,
                   Str:D :$valuesFrom,
                   Str:D :$automaticKeysTo = 'AutomaticKey',
                   :&aggregationFunction = &auto-aggregator) {

    ToWideFormat( @tbl, $identifierColName, $variablesFrom, $valuesFrom, :$automaticKeysTo, :&aggregationFunction)
}

#-----------------------------------------------------------
#| To long form conversion for arrays of hashes.
multi ToWideFormat(@tbl, $idColsSpec, Str:D $variableColName, Str:D $valueColName,
                     Str:D :$automaticKeysTo = 'AutomaticKey', :&aggregationFunction = &auto-aggregator) {

    # Coerce into array-of-hashes
    my Hash @arr-of-hashes;
    try {
        @arr-of-hashes = @tbl
    }

    if $! {
        note 'The first argument is expected to be an array that can be coerced into an array-of-hashes if the rest of the arguments are strings.';
        return Nil;
    }

    # All columns
    my @allCols = @arr-of-hashes[0].keys;

    # Determine ID columns
    my Str @idColsLocal;

    if !(so $idColsSpec) or $idColsSpec eq $[] or $idColsSpec.isa(Whatever) {

        @idColsLocal = [$automaticKeysTo];

        # Add automatic IDs.
        my $k = 0;
        @arr-of-hashes = @arr-of-hashes.map({ $_.push( [$automaticKeysTo] Z=> [$k++] ) });

        @allCols.push( $automaticKeysTo );

    } elsif $idColsSpec.isa(Str) and $idColsSpec.lc (elem) @allCols {

        @idColsLocal = [$idColsSpec]

    } else {
        try {
            @idColsLocal = $idColsSpec.list
        }

        if $! {
            note 'The second argument is expected to be a string or an array strings.';
            return Nil;
        }
    };

    if (@idColsLocal (&) @allCols).elems < @idColsLocal.elems {
        note "If the second arguments is not Nil or [] then it is expected to be a columns name of the dataset.";
        return Nil;
    }


    if $variableColName !(elem) @allCols or $valueColName !(elem) @allCols {
        note "If the third and fourth arguments are expected to be columns names of the dataset.";
        return Nil;
    }

    # Determine aggregation function
    if !&aggregationFunction { &aggregationFunction = &auto-aggregator; }

    # Break-down into groups
    my $sep = ' , ';
    my @res = @arr-of-hashes.categorize({ $_{ |@idColsLocal, $variableColName}.join($sep) });

    # Aggregate
    @res =
            do for @res -> $p {
                my $aggrRes = &aggregationFunction( $p.value.map({ $_{$valueColName} }) );

                # Delete the pair corresponding to the aggregated column
                my %h = $p.value[0];
                my $var = %h{$variableColName}:delete;
                %h{$valueColName}:delete;
                # %h{%h.keys.grep(* !(elem) [$valueColName])}:p

                %h.push( [$var] Z=> [$aggrRes] )
            };

    # Breakdown by ID columns only
    @res = @res.categorize({ $_{ |@idColsLocal }.join($sep) });

    # Make the wide form records
    @res =
            do for @res -> $p {
                # Merge the hashes for each unique combination of values from the ID columns
                my %hres;
                %hres = do for |$p.value -> %h {
                    %hres = %hres , %h
                }
            }

    # Result
    # Converting to a list since some of the operations produce Seq.
    return @res.sort({ $_{@idColsLocal} }).List;
}

root

Transpose

ToPrettyTable

React

=begin React :component<HeaderCol> :id<menu> 
=para L<Documentation|/doc/introduction>
=para L<Modules| /mods>
=para L<Examples| file:../examples/index.podlite>
=para L<Download |file:../download/index.podlite>
=para L<About|file:../about/index.podlite>
=para 🔍 K<⌘K>/K<ctrl-K>
=end React


=begin React :component<HeaderCol> :id<footer>  
=begin nested :!nested
=item1 B<Language>
    =item2 L<Get started|file:../getting-started/getting-started.podlite>
    =item2 L<Why Raku?|/doc/language/faq#Why-should-I-learn-Raku-What's-so-great-about-it>
    =item2 L<Try Raku|https://glot.io/new/raku>
    =item2 L<Raku cheat sheet|https://github.com/Raku/mu/blob/master/docs/Perl6/Cheatsheet/cheatsheet.txt>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<Raku on Exercism|https://exercism.org/tracks/raku>
    =item2 L<Wikipedia|https://en.wikipedia.org/wiki/Raku_(programming_language)>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=end nested
=begin nested :!nested

=item1 B<L<Documentation|/doc>>
    =item2 L<Getting started, Migration guides from other languages, & Tutorials | file:../doc/introduction.podlite>
    =item2 L<Language References|file:../doc/reference.podlite>
    =item2 L<Type Reference| file:../doc/types.podlite>
    =item2 L<Miscellaneous| file:../doc/miscellaneous.podlite>
    =item2 L<FAQs (Frequently Asked Questions)|/doc/language/faq>
    =item2 L<Community|/doc/language/community>
    =item2 L<The list of all documents|file:../doc/index.podlite>

=item1 B<Resources>
    =item2 L<The Raku Guide|https://raku.guide/>
    =item2 L<Books |https://perl6book.com/>
    =item2 L<Rosetta Code | https://www.raku.org/community/rosettacode>

=end nested
=begin nested :!nested

=item1 B<Resoures>
    =item2 L<Download | file:../download/index.podlite>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=item1 B<Learning>
    =item2 L<The Raku Guide|https://raku.guide/>
    =item2 L<Wikibook |https://en.wikibooks.org/wiki/Raku_Programming>
    =item2 L<Books |https://perl6book.com/>
    =item2 L<Rosetta Code | https://www.raku.org/community/rosettacode>
    =item2 L<Learn Raku in Y minutes|https://learnxinyminutes.com/docs/raku/>
    =item2 L<Golfing |https://github.com/AlexDaniel/raku-golf-cheatsheet>
=end nested
=begin nested :!nested

=item1 B<Explore>
    =item2 L<Raku Blog Aggregator|https://planet.raku.org/>
    =item2 L<Rakudo Weekly|https://rakudoweekly.blog/>
    =item2 L<The Weekly Challenge |https://perlweeklychallenge.org/>
    =item2 L<Raku Advent Calendar|https://raku-advent.blog/>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=end nested
=end React


=begin React :component<CookieConsent> :id<CookieConsent> :buttonCaption("Got it!")
=para
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=end React


ToWideFormat

Data::Reshapers::ToWideFormat

Data::Reshapers v0.1.9

Authors

License

Dependencies

Test Dependencies

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Documentation