Make every field as optional with Pydantic v2

utils.py

from copy import deepcopy
from typing import Any, Tuple

from pydantic import BaseModel, create_model, Field
from pydantic.fields import FieldInfo


def fields_optional(model: type[BaseModel]):
    def make_field_optional(
        field: FieldInfo, default: Any = None
    ) -> Tuple[Any, FieldInfo]:
        new = deepcopy(field)
        new.default = default
        # field as optional (type: ignore)
        new.annotation = Optional[field.annotation]
        return new.annotation, new

    return create_model(
        f"{model.__name__}",
        __base__=model,
        __module__=model.__module__,
        **{
            field_name: make_field_optional(field_info)
            for field_name, field_info in model.model_fields.items()
        },
    )


class SourceCreateSchema(BaseModel):
    name: str = Field(min_length=3, max_length=50)
    info: str = Field(min_length=20)


@fields_optional
class SourceUpdateSchema(SourceCreateSchema):
    ...