> Which is ironic because python and perl are extremely similar.

Would you mind expanding on this a bit? It's been a while since I did perl, but I remember it being fairly distinct from python, other than being a dynamically-typed "interpreted" language.

The feature set and type of problems that they are good at are similar. The personality of the language is not. But the translation is easy.

What is weird about Perl is that it is intentionally designed to use the part of our brain that parses syntax to encode a bunch of information. So $ means "the", @ means "these", and so on. The linguistic analogies are carried surprisingly far, and There Is More Than One Way To Do It is considered a feature.

By contrast Python tries to have a very simple and regular syntax. It has well-organized libraries. And aims to have one simple and right way to do it. (Though why their one way to handle opening external processes should be so Byzantine..well I digress.)

But both of them live in the space of dynamic interpreted libraries with similar kinds of introspection, similar native data structures and so on. Both take heavy advantage of the fact that between decent scalars, arrays, and hashes you can write algorithms for almost any problem which will perform within a constant factor of a theoretically ideal data structure. Therefore given the same problem it is natural to write the same solution in about the same way with very similar characteristics.

If you know one, learning to write the other isn't hard and the mental translation remains easy.

Oh, there are differences. Some things are easier to express directly in Perl. Like backticks. Python can let objects be used as keys in dictionaries. Perl's optional variable declarations catch a lot of minor bugs. Python's iterators/generators take a lot of work to replicate in Perl. (Yes, there are CPAN modules that make it doable. Have we agreed on which one is right?)

But on the whole for most code, you tackle it in the same way, with equivalent data structures and naturally organize it similarly using the same strategies.

Compare and contrast with, say, Java.

The fact that they are so close puts them in a natural competition. And there, well, Perl is not popular for new projects while Python is one of the most popular languages out there. All the cool new integrations are made available in Python first and Perl is an afterthought. If they are too similar to co-exist without competition, it is clear which one is going to win. And it isn't Perl.

> Python can let objects be used as keys in dictionaries.

In Perl 6 object hashes allow you to do the same (https://docs.perl6.org/language/hashmap#index-entry-object_h...). If you're only interested in checking for existence, you can use a Set (https://docs.perl6.org/type/Set). If you want to just count the number of occurrences, you can use a Bag (https://docs.perl6.org/type/Bag).

> Perl's optional variable declarations catch a lot of minor bugs.

In Perl 6, variable declarations are obligatory by default.

> Python's iterators/generators take a lot of work to replicate in Perl.

In Perl 6 there is an easy to use interface for creating iterators (https://docs.perl6.org/type/Iterator)

All of these features are built-in, so no module loading is necessary.

I do not think of Perl 6 as Perl, despite the naming and people involved. I believe that it is as easy to migrate from Perl 5 to another scripting language as it is to migrate to Perl 6.

Furthermore the last I heard, Perl 6 performance was a disaster story. And libraries + real world adoption is kinda thin on the ground. Therefore other scripting languages (particularly JavaScript and Python) are more compelling targets to migrate to.

Has this picture brightened in the last year or so?

> I do not think of Perl 6 as Perl, despite the naming and people involved. I believe that it is as easy to migrate from Perl 5 to another scripting language as it is to migrate to Perl 6.

These beliefs are shared by most users of both languages, which makes bringing up Perl 6's capabilities in a Perl vs Python discussion confusing.

I would say so, yes. For instance, basic object creation in Perl 6 is now faster than basic object creation in Perl 5. Both can be improved with some tricks that experienced developers know, such as not using accessors in Perl 5, but directly lookup keys in the underlying hash. Similarly in Perl 6 some tricks can be performed. And then still Perl 6 is faster. Introducing Moo or Moose on the Perl 6 side, will only make Perl 5 slower.

Making things faster in Perl 6 has been the main focus of development in the past 3 years.

See also our most recent teaser for the 6.d release: https://i.redd.it/et514ut106u11.jpg which shows that the use of set operators has become almost 50x faster in that period.

> Python can let objects be used as keys in dictionaries

You can do this in perl too with a core (since perl 5.004) module. https://metacpan.org/pod/Tie::RefHash.

Their type systems, object model and reflection capabilities are very alike.

It's been a long while since I've developed anything serious in Perl, but the main difference I find between Python and Perl, aside from the syntax, is the value/reference split: Python makes every (passed) value a reference implicitly, Perl uses references explicitly, that can affect an architecture in important ways.

Indeed. I managed to program Python a few years before really taking note of that difference. Couldn't understand why my data structures kept being corrupted. Ahem.

FWIW, in Perl 6, references do not exist at the language level. At the implementation level, you could argue that everything is passed by reference. Perhaps you may find https://opensource.com/article/18/8/containers-perl-6 enlightning.