isort incompatibilites with lowercase, MixedCase, UPPERCASE

[andersk]

isort --profile=black --ca:

import lowercase
import MixedCase
import UPPERCASE
from module import UPPERCASE, MixedCase, lowercase

ruff --select=I:

import MixedCase
import UPPERCASE
import lowercase
from module import MixedCase, UPPERCASE, lowercase

[charliermarsh]

Nice, thank you.

[charliermarsh]

This is described and controlled by the order_by_type option.

Do we like this? I don't feel strongly about it.

[charliermarsh]

To phrase it differently: ignoring isort compatibility, would we want this behavior? (I think it's worth implementing for compatibility purposes.)

[charliermarsh]

Interestingly, it looks like this just applies to import from members. For import statements, isort sorts in a non-case-sensitive way (which I also find surprising! but it's probably rare to have cased module names anyway?).

[charliermarsh]

(At the very least, making this clearer in #676.)

[andersk]

Yeah, I think compatibility is the main value.

In Zulip, the diff for combine_as_imports = true would be +51 −65: fine, if that’s likely to be the future isort default, and it is a bit more compact. The diff for order_by_type = false + case_sensitive = true would be a further +80 −78: not abhorrent, but would be nicer to avoid, if there’s no particular rationale either way.

I noticed another effect of case-sensitivity:

-from typing import Type, TypeVar, TypedDict
+from typing import Type, TypedDict, TypeVar

which would maybe a weak argument in favor, except that the effect on all-uppercase names is exactly the opposite:

-from loud_typing import TYPE, TYPED_DICT, TYPE_VAR
+from loud_typing import TYPE, TYPE_VAR, TYPED_DICT

🤷

Uppercase modules are indeed rare but do exist: Zulip uses DNS and PIL.

[charliermarsh]

Haha yeah, now that I'm being forced to confront it, I find the isort behavior pretty confusing. I wish it was all just lexicographic sorting? But like most stylistic issues, I don't have a strong opinion as long as some standard is consistently enforced, and so it makes sense to me to prioritize isort compatibility.