$ cat example.py
s = ('111111111111111111111'
     '222222222222222222222')
$ black example.py
reformatted example.py
All done! ✨ 🍰 ✨
1 file reformatted.
$ cat example.py
s = "111111111111111111111" "222222222222222222222"
$ flake8 example.py
example.py:1:28: ISC001 implicitly concatenated string literals on one line
$ edit example.py # Remove the " " and save
$ cat example.py
s = "111111111111111111111222222222222222222222"
$ black example.py
All done! ✨ 🍰 ✨
1 file left unchanged.
$ flake8 example.py
$