PEP 751: one last time

[brettcannon]

@pf_moore

@groodt

It does sound like there’s always scope for implementers not to support it too.

There’s scope for lockers to not support (or rather, use) it. Installers will need to support the full format, otherwise it’s not much of a standard

But it’s not a huge burden from the installer side, as far as I can see.

Hopefully it isn’t too much of a burden since I just updated the PEP to require it for installers! PEP 751 – A file format to record Python dependencies for installation reproducibility | peps.python.org

The diff is at PEP 751: drop `packages.direct` and add `extras` and `dependency-grou… · python/peps@5d27124 · GitHub , but the highlights are:

• Add the marker expression syntax proposal we have all been talking about
• Added some stuff to “How to Teach This” as @pf_moore requested
• Dropped packages.direct, made packages.archive support sdists and wheels, and clarified that packages.archive, packages.directory, and packages.vcs imply a direct URL install (as suggested by @sbidoul )

I still plan to update my PoC for the PEP, but at this point I’m only planning to remove features as requested unless some horrible oversight is found that would cause the PEP to be rejected.