PEP 771: Renamed default-optional-dependency-keys to default-extras

[astrofrog]

I originally used default-optional-dependency-keys because it seemed to me like pyproject.toml avoided the terminology of extras, but @ncoghlan pointed out in https://discuss.python.org/t/pep-771-default-extras-for-python-software-packages-round-2/94905/2 that the specification for optional dependencies in pyproject.toml uses the term extra to refer to the optional dependency keys, which means we can use default-extras instead of default-optional-dependency-keys (which is a name that a lot of people have complained about). Since this change is a no-brainer and there have not been any objections since it was suggested, I am making the change straight away to avoid it being brought up again by others.

FYI @DEKHTIARJonathan and @pradyunsg

[DEKHTIARJonathan]

@astrofrog shall we take the opportunity to emphasize the comment from Paul about pip freeze

https://discuss.python.org/t/pep-771-default-extras-for-python-software-packages-round-2/94905/5

I think this is something that should be left for pip to decide. In fact, we can’t include it in the standard as requirements files and the pip freeze format aren’t standardised. My personal view is that I don’t want the output of pip freeze littered with [] just in case projects define default extras. The output of pip freeze isn’t just a “dumb lockfile” format, it’s also used for human consumption, and for various scripting use cases. As such, I’d rather it stayed human-readable.

Also I would keep this PR open for a week or so - might become the last revision before submission for decision.
CC: @warsaw

[astrofrog]

@DEKHTIARJonathan I thought it would be easier to fix this one specific issue in a standalone PR since it is pretty clear cut and just have that be merged soon just to make it easier for anyone reviewing the PEP. But if you'd rather we wait for any other updates we can do that too!

[pradyunsg]

Since this change is a no-brainer and there have not been any objections since it was suggested, I am making the change straight away to avoid it being brought up again by others.

Whoops, I brought it up again. FWIW, a day isn't really a lot of time for people to respond on d.p.o. 😅

To be fair, this is a somewhat bikeshed heavy aspect of the PEP anyway so it's reasonable to make a choice either way in the text to have the discussion focus on more... semantically significant aspects of the PEP.

[pradyunsg]

Change is OK to merge with my sponsor hat on.

[warsaw]

Well, at least this bikeshed is shorter, so 🥳

[zanieb]

Whoops, I brought it up again. FWIW, a day isn't really a lot of time for people to respond on d.p.o.

Yeah, I definitely agree with this. I don't think this change is a no-brainer. I think it's fine to merge — but I'll voice my concerns in the DPO thread.

[astrofrog]

Yes I think I jumped the gun on this - I will convert this to a draft and can update it later once there is consensus on this (and any other changes needed)