Pydantic - Find key in JSON File to use for object creation

Question

Is there any way to write a custom json fileparser for a pydantic class? I have json files that have multiple objects configured in them and want to use the value of the objectname for the creation of the object.

// config.json
{
    "object_type_1": {
                        "name" : "test1",
                        "value" : "mock",
                     },
    "totally_different_object" : {
                         "color" : "blue",
                         "something" : "else",
}

I would like to write someting like

from pydantic import BaseModel
class ObjectType1(BaseModel):
       name : str
       value : str

object_typ_1_example = ObjectType1.parse_file("config.json", object_key = "object_type_1")

But I couldn't find any example