🔒 Why does pyautogui's locate function return None instead of ImageNotFoundException?

[ashen flame]

My packages are up to date

[boreal glen]

@ashen flame

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[versed nymph]

what version do you have installed?

[ashen flame]

of pyautogui? 0.9.54

[chilly crag]

I wonder if the typehints are directly in the pyautogui source code, or if it's a .pyi from somewhere

[carmine depot]

Yeah, it looks like pylance has the idea that it could still return None, and thus complains.

You can test this: run it with some image known not to be found, see if it raises or returns None.

@ashen flame ^^

[ashen flame]

Tried it, do i just make pylance ignore it ?

[chilly crag]

or how about... tell us what happened?

[versed nymph]

seems fine to me. Are you looping or iterating the result of the locateCenterOnScreen?

[ashen flame]

It’s not that it’s not working, it’s just that my editor is raising an error

[versed nymph]

the error is saying that its not iterable. hence, my question

"None" is not iterable

[chilly crag]

according to the docs, it shouldn't be equal to None, but instead raise an error

[chilly crag]

what was the outcome?

[ashen flame]

Yea it works

[chilly crag]

wdym "works"

it was "does it raise, or does it return None"

[ashen flame]

imagenotfound exception, yes

[chilly crag]

ok, so it is an issue with pylance not knowing the current typehints

https://github.com/python/typeshed/blob/main/stubs/PyAutoGUI/pyautogui/__init__.pyi
leads to
https://github.com/python/typeshed/blob/f8cdc0bd526301e873cd952eb0d457bdf2554e57/stubs/PyScreeze/pyscreeze/__init__.pyi#L140

and this still says that it can return None

[carmine depot]

@ashen flame you can suppress specific complaints as described here: https://microsoft.github.io/pyright/#/comments?id=line-level-diagnostic-suppression
(Pylance seems to use pyright for the type checking. I think. From following some links.)

So see if adding # type: ignore to the end of the line with the complaint. I'd be interested to know the result.

[chilly crag]

I would personally use typing.cast()

[carmine depot]

Maybe. Can you? For this? My knowledge of that is slight.

I was just going for shutting up pylance.

[chilly crag]

from typing import cast
def f() -> str | None: ...
print(cast(str, f()).lower())

similar to this

it depends on what the full line of code is i guess

[boreal glen]

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