E201 / E202 false positives inside f-strings for Python 3.12

[vanschelven]

I have f-strings like so:

f"{ parts.scheme }://{ public_key }@{ parts.hostname }"

On Python 3.11 and below pycodestyle (via flake8) is happy with them. On Python 3.12 I get E201 and E202 (whitespace after '{', whitespace before '}')

This error is surprising to me, and "fixing" it makes the code much harder to read. Thoughts:

• Pep8 cannot really be a guidance here, because it predates f-strings (by far)
• Is it the position of the pycodestyle developers that whitespace-rules should be applied equally inside and outside f-strings?
• Whatever the position on what the correct behavior is, it's "surprising" (i.e. a bug) that the behavior depends on your Python version.
• On a more or less recent discussion about the modification of the f-string syntax, a Python core dev explicitly mentions the OK-ness of whitespace inside f-strings

Finally, and this is the best part: what if you want whitespace around the equals sign? [..] no problem; whitespace is preserved from the original text inside the curly braces [..] we also explicitly permit, and preserve, whitespace.

Similar discussions (sometimes prematurely marked as resolved):

• https://stackoverflow.com/questions/77224809/does-f-string-float-formatting-really-violate-pep-8
• Whitespace issues with Python 3.12 flake8#1876
• False positive E202 and E251 inside f-string (Python 3.12) #1201

====

>>> pycodestyle.__version__
'2.12.1'

[asottile]

you found the duplicates with answers please don't make new duplicates