add .pre-commit-config.yaml

[RoyStegeman]

I did not keep known_first_party. I tested it on model_trainer.py and it put the numpy import inside the n3fit imports while separating from n3fit import model_gen (not sure what's going on there). I also realised that we missed e.g. ekobox.

isort seems to recognise that nnpdf_data, validphys and n3fit are part of this repo so I think that's good enough (let's keep an eye on it though).

I'm not if favour of a CI test

[scarlehoff]

Why did you remove it from the global .toml, wouldn't it be better to have it there?

If black and isort from pre-commit don't recognize it (they should) you can explictly say --config pyproject.toml or similar.

That way one can use black on isort with your ide and make sure that it is using the same options.

(I guess we want to also check -but not autocommit the fixes- as part of the checks)

[RoyStegeman]

Why did you remove it from the global .toml, wouldn't it be better to have it there?

Because pre-commit cannot use the pyproject.toml file pre-commit/pre-commit#1165

If black and isort from pre-commit don't recognize it (they should) you can explictly say --config pyproject.toml or similar.

I thought there was no such option for isort and didn't really see the benefit. But I guess if you want to run it from the ide that's indeed not possible this way. I was wrong though, and isort does have an option --settings-path that I think do the job so I'll change it again.

(I guess we want to also check -but not autocommit the fixes- as part of the checks)

I'm not so sure, there may be cases in which we don't want to do exactly what black or isort wants. Or maybe not. Either way, let's see, if people adopt pre-commit problems about forgetting to run black should become rare.

[scarlehoff]

I don't know about pre-commit, but the tools you run inside certainly can (this is used in pineko or pinefarm)

[RoyStegeman]

Not for black and isort

[RoyStegeman]

Not sure what the problem is, but at least black doesn't seem to recognise the settings from pyproject.toml. I also still need to update the mentions of black and isort in the docs, but for now I've wrestled enough with this.

[scarlehoff]

thanks!
Since you are at it, it might be a good idea to remove the link to the old vp guide from https://github.com/NNPDF/nnpdf/tree/master/doc#currently-documented

(I think we already moved part of the stuff to the standard docs)