Notes

Use the Default Flake8 Ignores

Flake8 provides a way to ignore PEP8 rules through its --ignore and --extend-ignore flags. The former overwrites a default list of errors and warnings, including W503 and W504 which are mutually incompatible. Therefore, using --ignore will implicitly enable both of these mutually incompatible rules. It’s better to use --extend-ignore and not use --ignore when running flake8. In .flake8 config files, use

[flake8]
extend-ignore = ...

instead of

[flake8]
ignore = ...