The Python part could be the standard ruff.
Regarding C code, I personally prefer CPython formatting style.
It is not very formal, but I think we can setup https://zed0.co.uk/clang-format-configurator/ to get a config which is at least very close to CPython style.

The only challenge is figuring out the meaning of these dozens of options.

          might be nice to format the C code with something like https://github.com/ratgdo/esphome-ratgdo/blob/05967a5cb1e27341e55917188c79ca80a610da5f/.pre-commit-config.yaml#L10 as well (no preferences on the settings, other than to not have to think about it)

Originally posted by @bdraco in #1116 (comment)