You can use model_serializer:

from datetime import datetime

from pydantic import BaseModel, Field, model_serializer

class obj(BaseModel):
    resource: str
    resourceid: int
    resourceTime: datetime
    name: str
    option1: str = Field(exclude=True)
    option2: int = Field(exclude=True)

    @model_serializer(mode="wrap")
    def _serialize(self, handler):
        d = handler(self)
        d["resourceid"] = str(d["resourceid"])
        d["attributes"] = [
            {
                "name": "option1",
                "value": self.option1
            },
            {
                "name": "option2",
                "value": self.option2
            },
            {
                "name": "name",
                "value": self.name
            },
        ]
        return d

o = obj.model_validate(
    {
        "resource": "TEST",
        "resourceid": "1234",
        "resourceTime": "2024-09-03 00:00:00",
        "option1": "test",
        "option2": 23421,
        "name": "test"
    }
)

print(o.model_dump())

UPD:

To achieve dynamic behavior you can do something like this:

class obj(BaseModel):
    resource: str
    resourceid: int
    resourceTime: datetime
    name: str
    option1: str = Field(exclude=True)
    option2: int = Field(exclude=True)

    @model_serializer(mode="wrap")
    def _serialize(self, handler):
        d = handler(self)
        d["resourceid"] = str(d["resourceid"])
        attributes = [
            {
                "name": "name",
                "value": self.name
            },
        ]
        for field_name in self.model_fields.keys():
            if d.get(field_name) is None:
                attributes.append(
                    {"name": field_name, "value": getattr(self, field_name)}
                )
        d["attributes"] = attributes

        return d

This implementation will add to the attributes all fields marked as exclude=True plus the name field

Thanks.

from typing import Literal
from datetime import datetime
from pydantic import BaseModel, model_serializer, Field

class A(BaseModel):
    resource: str = Field(serialization_alias="RESOURCE")
    resourceid: int
    resourceTime: datetime
    name: str
    option1: str = Field(exclude=True)
    option2: int = Field(exclude=True)

    @model_serializer(mode="wrap")
    def test(self, handler):
        d = handler(self)
        d["attributes"] = [{ "name": k, "value": v } for k,v in self.__dict__.items()]

        return d

o = A(
    **{
        "resource": "TEST",
        "resourceid": "1234",
        "resourceTime": "2024-09-03 00:00:00",
        "option1": "test",
        "option2": 23421,
        "name": "test"
    }
)

print (o.model_dump_json(indent=2, by_alias=True))

And I have:

{
  "RESOURCE": "TEST",
  "resourceid": 1234,
  "resourceTime": "2024-09-03T00:00:00",
  "name": "test",
  "attributes": [
    {
      "name": "resource",
      "value": "TEST"
    },
    {
      "name": "resourceid",
      "value": 1234
    },
    {
      "name": "resourceTime",
      "value": "2024-09-03T00:00:00"
    },
    {
      "name": "name",
      "value": "test"
    },
    {
      "name": "option1",
      "value": "test"
    },
    {
      "name": "option2",
      "value": 23421
    }
  ]
}

So in this way I could only fields for validation.

The only drawback that I lose some Pydantic features on values that are in loop attribute (ex. by_alias=True). That is acceptable for my case.