Strange Typing problem

[j29scott]

We have the following class annotation:
dps: AnnotatedSortedList[Datapoint]

But when doing a return self.dps[i] on a later member method:

Returning Any from function declared to return "Datapoint" [no-any-return]

Any tips?

[jayqi]

Hi @j29scott,

Can you please provide some more information about what you're doing:

• Is the error you're getting a runtime error or a static typechecking error? If static typechecking error, which typechecker are you using?
  • This looks like it's mypy to me, but please confirm.
  • Does the code still work as expected when actually running it?
• What is Datapoint? Is it another Pydantic model? Is it some custom class?

To the extent that you're able to, any source you can provide for the member method or the Pydantic model definition would be helpful in trying to understand what's happening.

[j29scott]

It is not a runtime error, a type checking error. It is mypy, the code behaves as expected when running it. Datapoint is a custom class. It was not literally a BaseModel, but a complicated wrapper around one.

If the error isn't obvious, I'll try to create a minimal example later today or tomorrow.

[jayqi]

Hi @j29scott,

Thanks for clarifying. I'm not sure why there's a typechecking error. A minimal example, along with your sortedcontainers-pydantic, Pydantic, mypy, and Python versions would be great.

[pjbull]

Also, what is the type hinting on the method itself?

[j29scott]

from sortedcontainers_pydantic import AnnotatedSortedList

class Item:
    foo: int

class Container:
    objects: AnnotatedSortedList[Item]
    def __getitem__(self, index: int) -> Item:
        return self.objects[index]

$ mypy test.py 
test.py:9: error: Returning Any from function declared to return "Item"  [no-any-return]
Found 1 error in 1 file (checked 1 source file)

[j29scott]

python 3.12
sortedcontainers-pydantic = "~2.0.0"
mypy = "~1.13.0"

[jayqi]

@j29scott if you install sortedcontainers-stubs, does that fix the error?

[j29scott]

@j29scott if you install sortedcontainers-stubs, does that fix the error?

I will try soon... is it not a requirement ?

[jayqi]

It's a community-maintained stubs-only package for sortedcontainers that is only used for typechecking. It's not a runtime dependency for sortedcontainers or for sortedcontainers-pydantic.

I don't think it makes sense to add as a dependency directly, but maybe some paths forward are:

• Document that this may be needed for typechecking
• Maybe add a [typing] extra that would install it