Fix hound with a bit better flake8 setup

[davidlatwe]

What's changed

• Decided which rule to follow, line break before binary operator or after.
• Added exclude, so flake8 won't look into modules that can be ignored when invoking flake8 on local.

Discussion

Which should we follow ?

1) Write with line break before binary op (W503)

foo = ("hello"
       + "world,"
       + "bar")

or,

2) write line break after binary op (W504)

foo = ("hello" +
       "world," +
       "bar")

I now like to break before (option 1), since I can view all the operations in a aligned stack, what do you guys think ?

Additional notes

How to invoke flake8 on local

$ pip install flake8
$ cd avalon-core
$ flake8

[tokejepsen]

Personally I would vote for option 2 because its easier to read.

[davidlatwe]

Hmmm, I remember that Pype club also take option 2 as well, any other inputs ? @mottosso @BigRoy

[mottosso]

Needs more examples to tell. With the plain-text example, option 2 looks better. Because all operators are the same. But with more mathy stuff, I tend to prefer 1.

# Option 1
rotation = (some_matrix
            * Vector3(1, 0, 0)
            / 0.12
            % 2)

# Option 2
rotation = (some_matrix *
            Vector3(1, 0, 0) /
            0.12 %
            2)

Though I would probably add one more line, so as to not depend on the length of the variable name.

rotation = (
    some_matrix
    * Vector3(1, 0, 0)
    / 0.12
    % 2
)

translation_with_longer_name = (
    some_matrix
    * Vector2(1, 0, 0)
    / 613.1
    * 100
)

Since we can only have one option for all occurrences, and since strings don't technically need the + anyway, I'd vote for option 1. 👍

[davidlatwe]

Good example !

[jasperges]

Personally I prefer the linebreak before the a binary operator, because you can immediately see the operator. https://www.python.org/dev/peps/pep-0008/#should-a-line-break-before-or-after-a-binary-operator

Not necessarily a good reason, but Black also does it like this. At first I wasn't a fan of Black, but now I quite like it actually. It makes your code formatting consistent.

[BigRoy]

I'm honestly fine with either. I'd be inclined to go with linebreak before the a binary operator if that's PEP8. However, I don't necessarily prefer one over the other.

As it's currently a tie (if pype really uses option 2) I'll have them add an opinion directly @antirotor @mkolar @iLLiCiTiT

Then I guess we should just pull the trigger. :)

[iLLiCiTiT]

I'll have them add an opinion directly @antirotor @mkolar @iLLiCiTiT

I think we have different opinions about that as well. We've agreed to have binary operator before as you can easily see how the argument affect result.

I personaly also preffer to add one more line to not depend on line length of variable name, the one more line enhance readability of the content for me.

[antirotor]

It is also possible to merge all kinds of config files into one - setup.cfg. There you can create [flake8] section and rest is the same. There can also be coverage, pytest, tox and most of other similar tools, reducing amount of files in repository root. Just for consideration...

[mkolar]

This got hanging here a bit :). So I'll add my two cents. I also prefer line break before binary operators. For the same reasons mentioned already. I find it somewhat easier to quickly scan the code and see what's happening with that.

[davidlatwe]

Line break before binary op it is ! Let's merge this !!