PEP 803: expand motivation with maintainer comments

[ngoldbaum]

@warsaw told me he'd like to see sections like this in C API PEPs. I checked with @encukou and he said he's happy for me to add this section and he thinks it improves the PEP. He already reviewed an earlier version of this text privately.

I've added myself as a PEP author, let me know if that's not the correct thing to do.

I might expand this with more quotes if I get more responses to queries I've sent out over the past couple of days.

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📚 Documentation preview 📚: https://pep-previews--4831.org.readthedocs.build/

[MLopez-Ibanez]

Hi @ngoldbaum I am happy if you want to quote me in the way you did, but I think the first quote detracts from your point due to my mistake of calling the free-threaded version experimental, when it is not. What I meant is that there is no stable API that would avoid having to build wheels for each new version of Python, which is precisely what I wish to avoid. Feel free to paraphrase me instead of quoting me.

[MLopez-Ibanez]

This sentence: "It has a much smaller userbase than cryptography and has a smaller appetite for build complexity" makes it sound like the latter is an explanation for the former. The rationale for avoiding build complexity is a smaller developer base rather than userbase. Even if our userbase was larger, we would still aim to avoid build complexity (in particular, not having to chase new Python versions).

Also, one should maybe put "smaller userbase" in perspective to not detract from your argument (why should Python developers care about the needs of a Python package that nobody uses?) : moocore is now a hard-dependency of pymoo, which is among the top %1 Python packages according to https://clickpy.clickhouse.com/dashboard/pymoo Thus, moocore will reach the top %1 as old versions of pymoo are phased out.

[ngoldbaum]

Also, one should maybe put "smaller userbase" in perspective to not detract from your argument (why should Python developers care about the needs of a Python package that nobody uses?) : moocore is now a hard-dependency of pymoo, which is among the top %1 Python packages according to https://clickpy.clickhouse.com/dashboard/pymoo Thus, moocore will reach the top %1 as old versions of pymoo are phased out.

Good point, I'm just going to delete that whole sentence. It doesn't add anything. I also edited the last paragraph and your quote. Thanks for looking this over!

[ogrisel]

Another extra benefit: once major upstream projects ship stable ABI wheels (e.g. numpy and scipy), it will be easier for downstream projects (e.g. scikit-learn) to run their own tests against the main branch of CPython (or a specific PR branch) without having to rebuild those upstream dependencies from source (which can be computationally or operationally expensive).