Randomly return `None` in `Optional` fields about polyfactory

[lyz-code]

Works like a charm, thank you! :)

[Goldziher]

Hi @Goldziher first of all, thank you, thank you and thank you. I've been close to create something like this several times. You're a life saver :)

In most of my pydantic models I have some property of type Optional[...]. It would be awesome if pydantic-factories was able to understand them and randomly return None on some of the objects.

I dealt with this problem in the past, and created faker-optional a faker provider just for that, maybe it's interesting for this use case.

Thanks!

Why you're welcome 😄

So, regarding your question, given:

class MyModel(BaseModel):
     prop: Optional[str]

You would like the factory to occasionally return None and occasionally return a string for prop?

I can certainly add this, or if you like - you can add a PR adding this functionality. Let me know how you'd like to proceed. I wouldn't though like to add a dependency for this - it can be done quite easily with the existing implementation.

[lyz-code]

Yup, that functionality is exactly what I had in mind, and I fully understand that it's not reason to add another dependency.

Regarding who implements it, if you can (and want to) do it, probably you'll be able to do it faster, else I can do it myself. In that case, I'd be grateful if you can point me on how you think it should be implemented.

[Goldziher]

@lyz-code - implemented, and released as v0.4.1. The factory will randomly output None values for optional fields - except for dataclasses, for these it will always output values for now. It will require more custom logic to handle this because the pydantic helper function create_model neither allows for setting required via field definitions, nor runs the pydantic parsing logic.

I, or someone else, will need to solve this somehow. But I think this should be sufficient for most use-cases.