pycodestyleにおけるW503とW504の議論
Should a Line Break Before or After a Binary Operator?
（PEP 8の変更）を受けて
Update handling of breaking around binary operators: W503 vs W504 #498
https://mail.python.org/pipermail/python-ideas/2016-April/039774.html
let's change the PEP! (Guido-san)
（methaneさんコメントある）
PR
https://github.com/PyCQA/pycodestyle/pull/502
default ignore W504
#flake8
側で参照
https://github.com/PyCQA/flake8/issues/494#issuecomment-812812089
（W503 shouldn't exist）
RuffにおけるW503とW504