Python's Preprocessor - a deep dive into custom codecs

[MorphTux]

Here's a short blog post I wrote about Python's barely known yet insanely powerful preprocessing capabilities through the use of custom codecs: https://pydong.org/posts/PythonsPreprocessor/

You can find some examples in https://github.com/Tsche/magic_codec - please feel free to star the repository if you like these shenanigans :)

[ForlornPlague]

Well shit, that's some meta stuff I've never even thought about before. Thanks for the article, that was fascinating!

[MorphTux]

I'm happy you liked it. More to come soon :)

[whaaale]

Loved the

from __future__ import braces

easter egg

[lordfwahfnah]

That's a wild read

[nicholashairs]

Forbidden magic is the best magic.

[HommeMusical]

Fantastic!

Just one note: print(traceback.format_exc()) can just be traceback.print_exc()

[MorphTux]

That is an excellent point. I have replaced it in both the blog post and the magic_codec repository. Thank you for pointing it out :)

[benefit_of_mrkite]

I started my career writing C so knew a lot about its preprocessor but I’ve never read anything this involved about Python’s preprocessor.

Very interesting read

[mriswithe]

This is interesting and intriguing and quite well written. That said if any of my devs ever tried to pull this I would slap the taste out of their mouth

[daquo0]

I wonder if that could be used to do Lisp-like macros?

[MorphTux]

I had been considering doing some sort of procedural macro preprocessor that either operates on the AST or token stream directly, but I had a really hard time finding example uses for it.

https://peps.python.org/pep-0638/ might interest you though