Make luigi package more flake8 compliant

[ediskandarov]

Motivation of this PR was to make flake8 checks as strict as possible.

Before:

commands = flake8 --max-line-length=384 --exclude=doc,test,luigi/six.py
  flake8 --max-line-length=100 --ignore=E265 doc
  flake8 --max-line-length=252 --ignore=F401,F841 test

After:

commands = flake8 --max-line-length=160 --exclude=doc,luigi/six.py
   flake8 --max-line-length=100 --ignore=E265 doc

This will protect luigi package from govnokod.

In future max-line-length should be less then 120 chars for better readability.

[Tarrasch]

I thought \ were unpythonic and one preferred parenthesis? No?

[ediskandarov]

I guess there is no more or less pythonic. In my opinion - pythonic mean better readable.

In some cases parenthesis better readable but in this case - this condition \ looks good. Condition must no be over-parenthesised.

https://www.python.org/dev/peps/pep-0008/#maximum-line-length

Backslashes may still be appropriate at times. For example, long, multiple with -statements cannot use implicit continuation, so backslashes are acceptable:

[Tarrasch]

Awesome progress, for future reference, this a continuation of #1174.

[Tarrasch]

Thanks so much for caring about the code quality of luigi! :)

[Tarrasch]

What's "govnokod" by the way? I only found results in Russian. :)

[ediskandarov]

Thanks so much for caring about the code quality of luigi! :)

We use luigi and loved it. I wish bright future for project. You are welcome. Thank you for your work too.

What's "govnokod" by the way?

Well.. It is very specific term. Usually govnokod generated by anything but not developers head. It is like monkey code but a little bit different.

Talk is cheap. I show you the code: http://govnokod.ru :-))

[Tarrasch]

Ah this looks so much nicer! :)

[Tarrasch]

This is so awesome! Thanks :)