Black and pycodestyle disagree about whitespace before :

[dmerejkowsky]

Operating system: Debian 9
Python version: python 3.6
Black version: 18.6b2
Does also happen on master: yes

Steps to reproduce:

# in foo.py 
a[len(b) :]

$ black --diff foo.py
All done! ✨ 🍰 ✨
1 file left unchanged.
$ pycodestyle foo.py
foo.py:1:9: E203 whitespace before ':'

This is unfortunate because I use pycodestyle for CI (not everyone can/want use to black yet), but I use black in my editor to format on save ...

Of course, a workaround is to use # fmt: off, but I still think this is a bug in black and should be fixed.

[JelleZijlstra]

pycodestyle is breaking PEP 8 here; see https://github.com/ambv/black#slices.

[ambv]

Turn off E203 and W503 and you can continue to use Black and pycodestyle.

[dmerejkowsky]

pycodestyle is breaking PEP 8 here

Woops, my bad. Sorry for the noise

[simonwiles]

For future readers (including, no doubt, me the next time I forget), @JelleZijlstra's link is now https://black.readthedocs.io/en/stable/the_black_code_style.html#slices.

[antgel]

That link in 2021: https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html#slices

Well, it is beta... ;)