typed_object_factory.py

import json
from typing import Any, TypedDict, Union, Callable, Optional
from typeguard import CollectionCheckStrategy, check_type


Serializer = Optional[Callable]


def typed_object_factory(object_type: Any, serializer: Serializer=None):
    class TypedObject:
        def __init__(self, obj: Any) -> None:
            self.object_type: Any = object_type
            self._serializer: Serializer = serializer
            self._object: Any = self.validate(obj)

        def validate(self, value: Any) -> Any:
            check_type(
                value,
                self.object_type,
                collection_check_strategy=CollectionCheckStrategy.ALL_ITEMS,
            )

            return value
        
        def serialize(self):
            if self._serializer:
                return self._serializer(self._object)
            raise NotImplementedError("No serializer defined.")
        
    return TypedObject
        

class TagType(TypedDict):
    name: str
    value: Union[str, int]


class ThingType(TypedDict):
    name: str
    id: int
    tags: list[TagType]    
    
    
Thing: object = typed_object_factory(ThingType, serializer=lambda v: json.dumps(v, indent=2))  

thing: Thing = Thing(  # succeeds
    {
        "name": "Foobar 2000",
        "id": 100,
        "tags": [
            {"name": "industry", "value": "Foo"},
            {"name": "utility", "value": "Foo preparation"},
        ]
    }
)

print(thing.serialize())