Addendum for PEP 722 to use TOML

I can’t speak for Brett, but personally, I’m not particularly happy if PEP 723 essentially says “like PEP 722, but with these differences” while proposing something that PEP 722 has explicitly rejected (in a lot of detail).

You’re welcome to take sections of text from PEP 722 and copy them into PEP 723, and it’s fine to say “PEP 722 does the following, this PEP proposes a different approach because (insert explanation here)”, but I think it’s unfair to presume that anything in PEP 722 can be taken without qualification to be in support of the proposal in PEP 723.

I assume this goes back to my comment

This was very specifically talking about “using TOML in place of a custom format” - not about the choices of parsing the code as text (i.e., using a “structured comment” approach), or not supporting the full pyproject.toml format, or any of the other choices made in PEP 722. Maybe that wasn’t clear enough, my apologies if so.

Obviously, people can propose any PEP that they want. But as the author of PEP 722, I object to it being used in support of a PEP that so drastically rejects the choices behind my proposal. By all means write such a PEP - having a concrete specification makes discussion of the details of the proposal much easier (after all, that’s been an ongoing problem with the “why not use pyproject.toml?” position[1], that it’s not clear what is meant) but suggesting that your proposal builds on mine, rather than replacing it, is frankly just misleading and incorrect.

Personally, I would much rather you started your PEP from scratch. It would save me a lot of time and effort pointing out things I’ve already stated, repeatedly, when arguing for the choices I made in PEP 722. I suspect it would also save a lot of your time, as you’d be spared having to go through all of the debates we’ve already had - and you’d still need to reflect the discussion in your PEP anyway, so you don’t save anything in the long run.

If I may offer one piece of advice, it’s that whenever we’ve had competing PEPs in the past, ones that have positioned themselves as “an alternative proposal to X” rather than as a complete proposal in their own right, have tended to fail - often over technical issues due to being underspecified or making unwarranted assumptions, rather than because the underlying ideas are bad.

But at the end of the day, do whatever you prefer - it will be up to Brett to decide.


  1. and one I spend a chunk of time addressing in PEP 722 ↩︎

4 Likes