Optional keywords on Objects/List or any other Datatypes that wraps other BaseModel

[victai]

For example:

class Dog(BaseModel):
  name: str
  breed: Optional[str]

class Cat(BaseModel):
  name: str
  breed: Optional[str]

class People(BaseModel):
  dogs: Optional[list[Dog]]
  cats: list[Cat]

When I ask the model to output People, currently Guard accepts this

{
  'dogs': [
    {'name': 'dog_name1'},
    {'name': 'dog_name2', 'breed': 'Chihuahua'}
  ]
  'cats': [
    {'name': 'cat_name1'}
  ]
}

But not this

{
  'cats': [
    {'name': 'cat_name1'}
  ]
}

The issue I'm facing is sometimes the model does not even output 'dogs': [] when the model thinks that there are no dogs in the prompt.

Quick Fix

I added

if not value:
    return validation

In the List and Object classes in guardrails/datatypes.py to workaround this. However, I'm not sure if there are potential risks by doing so.

class List(NonScalarType):
    """Element tag: `<list>`"""
    tag = "list"
    def collect_validation(
        self,
        key: str,
        value: Any,
        schema: Dict,
    ) -> FieldValidation:
        # Validators in the main list data type are applied to the list overall.
        validation = self._constructor_validation(key, value)

        if len(self._children) == 0:
            return validation
        if not value:
            return validation

[irgolic]

Hey, thanks for this issue, we'll look into it.