Read http://www.wikivs.com/wiki/Perl_vs_Python

To be honest the parent comment to yours first link reminds me of a rather lot of shell/perl created by people that treat things with the procedural mindset and just keep bashing their heads against a problem until it succeeds. There isn't anything wrong with that but that python really is no different stylistically than any of the "horrible perl" stories I've seen. I've seen perl that made most ruby look unreadable at first glance too. I think it really goes to show encrypting human thought into programming languages is not trivial. Also I'm getting sick of these $foo_language is better/worse/a threat(really threat? weird word choice imo) to anything. Every language I learn I learn something new in. Even if its the ones I don't like much like Java/PHP, doesn't mean they're bad languages or they're devoid of being able to teach you new ways to approach problems.

Meh, ranted longer about this than I'd thought I would.

To my mind, that's a success for Perl: it allows people who wouldn't otherwise be able to write programs to do so. Sure, they make messes--who doesn't at first?--but they get things done.

Shape class must have color attibute only. Shape::Retangle and Shape::Circle should inherit from the Shape.

And

...

package Shape::Retangle;

use parent 'Shape';

sub new {

    my ($class, $args) = @_; 

    my $self = $class->SUPER::new( { color => $args->{color} || 'black' } );

    $self->{length} = $args->{length} || 1;

    $self->{width}  = $args->{width} || 1;

    return bless $self, $class; 

...

package Shape::Circle;

use parent 'Shape';

sub new {

    my ($class, $args) = @_; 

    my $self = $class->SUPER::new( {color => $args->{color} || 'black' } );

    $self->{diameter} = $args->{diameter} || 1;

    return bless $self, $class; 

...