Enforce a code style

[ardunn]

e.g., black formatting.

https://github.com/python/black

[janosh]

I can recommend black in conjunction with flake8 which would do the style enforcing. For instance, this is the config I use (specified in setup.cfg):

[flake8]
max-line-length = 100
exclude = .git
# E731: do not assign a lambda expression, use a def
# W293: blank line contains whitespace
# E203: whitespace before ':'
# E265: block comment should start with '# '
# W503: line break before binary operator
ignore = E203, E731, W293, E265, W503

# make isort play nicely with black's import formatting
# https://github.com/microsoft/vscode-python/issues/5840
[isort]
multi_line_output = 3
include_trailing_comma = True

[utf]

I think using black is a great idea. I'm not sure about some of those exceptions though. Particularly, it seems useful to have checks for these:

# W293: blank line contains whitespace
# E203: whitespace before ':'
# E265: block comment should start with '# '
# W503: line break before binary operator

[janosh]

@utf Sure, I just copied those over from another project where they accumulated over time to act as an example.