[python linting] enforce all flake8 E & W codes besides some exceptions
This enforces all pycodestyle rules aside from the ones we currently
Current violations (some of these can be fixed fairly soon,
some are super prevalent)
E265 Block comment should start with '# ' E501 Line too long (82 > 79 characters) E704 Multiple statements on one line (def) E712 Comparison to true should be 'if cond is true:' or 'if cond:' E713 Test for membership should be 'not in' E722 do not use bare except E731 Do not assign a lambda expression, use a def W503 Line break occurred before a binary operator W504 Line break occurred after a binary operator
These rules aren't often added and if we do get new rules causing issues,
they can be added as exceptions. Note that flake8 is fine if we tell it
to ignore a rule that it doesn't know about.
Flake8 min version has been bumped to 3.0 to support the simultaneous
--select and --ignore. I am guessing most of us are at least on 3.2.1
(ubuntu bionic / debian 9). I've tested on a variety of python / flake8
combinations and the seem to be agreeing that we are clean.
arc lint --everything
Reviewers: #bitcoin_abc, Fabien
Reviewed By: #bitcoin_abc, Fabien
Differential Revision: https://reviews.bitcoinabc.org/D5198