`Unused` type ?

[ar1ja]

hello

i run into problems sometimes when i have multiple unused arguments, for example :

    def get_func(
        self,
        clipboard: Any,
        selection_data: Any,
        info: Any,
        data: Any,
    ) -> None:
        """gets clipboard"""
        selection_data.set("BYTES", 8, data)

    def clear_func(self, clipboard: Any, data: Any) -> None:
        """clears clipboard"""

and linters dont like this, so maybe typing could have an Unused type ?

i mean currently ion have a type but i have this :

from typing import Any


class Unused:
    def __init__(self, *args: Any) -> None:
        del args

  def get_func(
        self,
        clipboard: Any,
        selection_data: Any,
        info: Any,
        data: Any,
    ) -> None:
        """gets clipboard"""
        Unused(clipboard, info)
        selection_data.set("BYTES", 8, data)

  def clear_func(self, clipboard: Any, data: Any) -> None:
        """clears clipboard"""
        Unused(clipboard, data)

which works fine, but maybe it should b a type like Unused[int] or Unused[Any] or smt

[erictraut]

It is very common in Python code for parameters to go unused, so I'm surprised that linters would flag that as a potential error. Which linter are you using, and is this rule enabled by default?

In any case, this doesn't seem to be related to static typing, so it probably doesn't make sense to add it to the static type system. It could be supported by linters as a (non-typing) annotation using the Annotated mechanism described in PEP 593. Linter authors would need to agree on a standard for this.

[hauntsaninja]

I agree with Eric that this doesn't belong in the type system. While Annotated is fine, I'm unsure why this needs a special mechanism at all. Your unused trick already just works. And it's unclear to me why having special cased symbols or annotations would be better than # noqa: unused-arg or whatever.

(Note that if you have an unused argument, but you'd like a type checker to complain if someone tries to pass it, annotating it as Never will usually do the trick)

[ar1ja]

It is very common in Python code for parameters to go unused, so I'm surprised that linters would flag that as a potential error. Which linter are you using, and is this rule enabled by default?

In any case, this doesn't seem to be related to static typing, so it probably doesn't make sense to add it to the static type system. It could be supported by linters as a (non-typing) annotation using the Annotated mechanism described in PEP 593. Linter authors would need to agree on a standard for this.

im using the pyright linter, but ye, i guess o

[erictraut]

im using the pyright linter, but ye, i guess o

I'm the author of pyright, so I can speak to this issue. First, I don't consider pyright a linter. It's a type checker. Second, pyright never emits an error for unused parameters. It does emit a "tagged" hint that tells your editor to display unused variables as "grayed out". (It emits these tagged hints only if the editor indicates that it supports them.) For example, here is how VS Code displays these:

Some editors unfortunately claim that they support these tagged hints but then display them the same as other diagnostics. I consider that a bug (or at least a design flaw) in those editors. If you're using one of those editors, you may want to disable tagged hints and/or report the issue to the maintainers of your editor.

[ar1ja]

im using the pyright linter, but ye, i guess o

I'm the author of pyright, so I can speak to this issue. First, I don't consider pyright a linter. It's a type checker. Second, pyright never emits an error for unused parameters. It does emit a "tagged" hint that tells your editor to display unused variables as "grayed out". (It emits these tagged hints only if the editor indicates that it supports them.) For example, here is how VS Code displays these:

Some editors unfortunately claim that they support these tagged hints but then display them the same as other diagnostics. I consider that a bug (or at least a design flaw) in those editors. If you're using one of those editors, you may want to disable tagged hints and/or report the issue to the maintainers of your editor.

a

well idk, it still annoys me seeing those things, it makes me feel like the code has a warning or smt, and when i run pyright it also throws tht and i hate tht so i hack around it sometimes, oh well tho

great work btw

[gvanrossum]

“Bye lol”

[ar1ja]

“Bye lol”

hm ?

[ar1ja]

i mean theres no interest in implementing this feature in typing and i do agree tht this isnt related to typing, but its the thing tht made most sense at the time for me, so i see no point in discussing this further

idk where else itd make sense

til then ill probably continue using del x or Unused(x) or smt, would b nice if python had smt like (void)x tho

or if ur refing to the informality of all of this when im getting formal responses, i just dont see the point in formality for things like this usually lol, im actually pretty scared of formality lmfao

[erictraut]

it still annoys me seeing those things

I'd find that annoying too. My point is that this is a problem with the way your editor is working (or is configured), not with pyright or with the type system. You should look to address the underlying problem, not complicate the Python type system as a workaround. I understand that one's choice in editors is very personal, but you might want to try switching editors if your current one is annoying you.

[ar1ja]

it still annoys me seeing those things

I'd find that annoying too. My point is that this is a problem with the way your editor is working (or is configured), not with pyright or with the type system. You should look to address the underlying problem, not complicate the Python type system as a workaround. I understand that one's choice in editors is very personal, but you might want to try switching editors if your current one is annoying you.

ye, ofc, i should change tht, welp, thanks for responding, have a good rest of ur day

[vitaly-krugl]

@hauntsaninja wrote:

I agree with Eric that this doesn't belong in the type system. While Annotated is fine, I'm unsure why this needs a special mechanism at all. Your unused trick already just works. And it's unclear to me why having special cased symbols or annotations would be better than # noqa: unused-arg or whatever.

(Note that if you have an unused argument, but you'd like a type checker to complain if someone tries to pass it, annotating it as Never will usually do the trick)

I tried Never with PyCharm, but it still displayed the "unused parameter" warning. So, this didn't suppress the warning:

from typing import Never

def mark_test_complete(self, node: WorkerController, item_index: int,
                           duration: Never):

It's just a shame that we have to resort to executing unnecessary statements, such as del duration or assert duration is duration, etc., just to suppress specific "unused parameter" warnings in some popular IDEs. I wouldn't want to suppress all "unused parameter" warnings since it might hide errors, only suppress the ones that I determined are legitimately unused.

[ar1ja]

@hauntsaninja wrote:

I agree with Eric that this doesn't belong in the type system. While Annotated is fine, I'm unsure why this needs a special mechanism at all. Your unused trick already just works. And it's unclear to me why having special cased symbols or annotations would be better than # noqa: unused-arg or whatever.
(Note that if you have an unused argument, but you'd like a type checker to complain if someone tries to pass it, annotating it as Never will usually do the trick)

I tried Never with PyCharm, but it still displayed the "unused parameter" warning. So, this didn't suppress the warning:

from typing import Never

def mark_test_complete(self, node: WorkerController, item_index: int,
                           duration: Never):

It's just a shame that we have to resort to executing unnecessary statements, such as del duration or assert duration is duration, etc., just to suppress specific "unused parameter" warnings in some popular IDEs. I wouldn't want to suppress all "unused parameter" warnings since it might hide errors, only suppress the ones that I determined are legitimately unused.

eh i honestly see no point in arguing this, its eh, if u wanna u can fork the linters u use and change them, although discussing here is probably not gonna change anything as the developers r not fond of adding this so eh