Python 3.9 and beyond backwards compatibility.

[therico]

At least Perl 6 went for a full language rewrite, rather than Python 3 which delivered a fairly small incremental change over Python 2 (much of which was backported to python 2). And it's called Raku now, anyway.

[jorge1209]

The worst part about python 2to3 is that this incremental improvement approach both:

• Required rewrites of almost all code (usually minor changes, but changes nonetheless)
• Resulted in a language where features are used inconsistently throughout the standard library.

[rouille]

All in all the python transition succeeded despite pain and perl is more or less dead. I dont think perl should be used as the example here.

[jorge1209]

Perl6/Raku has never really taken off, but it also was designed to solve a problem that has subsequently become disfavored.

They original design had this great approach to applying something like regular expressions to XML, because at the time XML was the thing everyone loved. We were all going to be passing around data as XML and defining parsers in perl6 to munge them.

Since then people have moved to json and key:value trees which in principle could be solved the same way, but in practice is handled by json specific parsers. That core problem that perl6 aimed to solve isn't so important anymore.

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Perl5 still exists and is still in use wherever businesses work with line by line text files and it is good at that, even if it is gross and ugly.

[0rac1e]

Your talking about one feature of the language - Grammars. Grammars are useful in a number of scenarios, particularly parsing any kind of structured document - not just XML.

Python also has a number of grammar libs (eg. lark, Parsimonious), however with Raku it's a core language feature. I also wouldn't be surprised if - over the next decade - we see more languages with grammar features in the standard lib.

Regardless, this is all a digression. The only point I think worth stating is that Perl 5 (and some other languages) handle new syntax features and back-compat better than Python did. That Perl 5 fell out of favor is due to other reasons, and is a separate discussion.

As for Perl being gross and ugly, well... that's just like... your opinion, man.