There is one case where the fix for PIE790 is not completely safe: it changes behavior when the placeholder statement is blocking a string from being a docstring.
$ ruff --version
ruff 0.5.5
$ cat pie790.py
pass
"docstring?"
print(f"{__doc__=}")
$ python pie790.py
__doc__=None
$ ruff check --isolated --fix --select PIE790 pie790.py
Found 1 error (1 fixed, 0 remaining).
$ python pie790.py
__doc__='docstring?'
There is one case where the fix for PIE790 is not completely safe: it changes behavior when the placeholder statement is blocking a string from being a docstring.