G'day ibm1620,

I think what you're looking for is splice.

Test script:

#!/usr/bin/env perl

use v5.36;
use constant {
    AREF    => 0,
    PYTHON  => 1,
    EXP     => 2,
};

use Test::More;

my @test_array = 'a' .. 'g';

my @tests = (
    [\@test_array, '[:3]',  'abc'],
    [\@test_array, '[:-3]', 'abcd'],
    [\@test_array, '[3:]',  'defg'],
    [\@test_array, '[-3:]', 'efg'],
);

plan tests => 0+@tests;

for my $test (@tests) {
    is get_array_slice_by_python_expr($test->@[AREF, PYTHON]),
        $test->[EXP], "Testing: $test->[PYTHON]";
}

sub get_array_slice_by_python_expr ($aref, $python) {
    state $re = qr{^\[(|-?\d+):(|-?\d+)\]$};
    my @temp_array = $aref->@*;
    my ($offset, $length) = $python =~ $re;
    $offset ||= 0;

    return length($length)
           ? join('', splice @temp_array, $offset, $length)
           : join('', splice @temp_array, $offset);
}
[download]

Output:

1..4
ok 1 - Testing: [:3]
ok 2 - Testing: [:-3]
ok 3 - Testing: [3:]
ok 4 - Testing: [-3:]
[download]