Look at flake8 B028

[enzbang]

Flake8 flags some code with the B028 check:

B028: Consider replacing f"'{foo}'" with f"{foo!r}" which is both easier to read and will escape quotes inside foo if that would appear. The check tries to filter out any format specs that are invalid together with !r. If you're using other conversion flags then e.g. f"'{foo!a}'" can be replaced with f"{ascii(foo)!r}". Not currently implemented for python<3.8 or str.format() calls.

Code should be rewritten following that advice or we should make the decision to ignore that warning.