Clarification regarding "hack"

[StefanBrand]

Hello, this project looks really interesting, but to me personally the use of "hack" in the README puts me off.

Basically this is a hack on the flake8's Application class

I propose to have this rewritten to

Basically this subclasses flake8's Application class

If you agree, I'm happy to create a PR. :)

Edit: I see there are a lot of references to "hacks" in the source code. Still, the badges are quite convincing, so maybe "hack" is an understatement.

[s-weigand]

The reason why I call it a hack is that the Application class of flake8 isn't part of the official API and it isn't supposed to be subclassed ( see this comment from the creator of flake8 )

The problem is that notebooks need to be a kind of Schrödiger-state, ignored and used at the same time.
flake8 can't be used directly on a notebook, since it internally is just a big JSON file, thus this tool needs to step in file discovery and replace the paths to the *.ipynb files with an intermediate python representation of the notebook, use flake8 on the intermediate files and map the errors back to their origin in the notebook. The only way I found to achieve this is by using Application in a way it isn't intended to be used.

Since Application isn't part of the official API, the internals also aren't as stable as an API would be, which is why I have scheduled tests against the default branch of flake8 and supported flake8 versions have an upper bound to the tested versions.

If you have a closer look at how the properties of Application are overwritten (monkey patching of runtime objects), you might understand why I think that hack is an appropriate term.

That said, being a hack doesn't mean it is bad software since it works as intended, but it denotes that Application is used in a way it isn't intended to be used.

[StefanBrand]

Ok, I understand better now, thanks for your explanation!

PS.: I've decided to go with nbqa as it supports both flake8 and black (and many other tools), which is quite comfortable for my use-case. :)

[MarcoGorelli]

Hi @StefanBrand - I'm glad you've found nbqa useful, though note that it's even more of a hack than flake8-nb 😳

[s-weigand]

@MarcoGorelli I wouldn't say nbQA is a hack, but a very sophisticated parsing wrapper around the tools which it supports. At least we don't monkey patch objects at runtime there 😝