Data Classes for Django QuerySet filters and exclutions proposal

django_filter_queryset_entities_proposal.py

from __future__ import annotations
from dataclasses import dataclass
from typing import Optional


class Model:
    def __init__(self, name: str, age: int) -> None:
        self.name = name
        self.age = age

    def filter(self, **kwargs):
        return kwargs

    def exclude(self, **kwargs):
        return kwargs


@dataclass
class Filters:
    name__icontains: Optional[str] = None
    age__gt: Optional[int] = None
    name__isnull: Optional[bool] = False

    def to_dict(self):
        return {
            key: value
            for key, value in self.__dict__.items()
            if value is not None
        }


@dataclass
class Exclutions(Filters):
    pass


if __name__ == "__main__":
    filters = Filters(name__icontains="V")
    exclutions = Exclutions(age__gt=18)
    model = Model(name="Viktor", age=20)

    filter_expected_result = {
        "name__icontains": "V",
    }
    exclutions_expected_result = {
        "age__gt": 18,
    }

    assert 'age_gt' not in filters.to_dict()
    assert 'name_isnull' not in filters.to_dict()

    assert 'name_gt' not in exclutions.to_dict()

    assert model.filter(**filters.to_dict()) == filter_expected_result
    assert model.exclude(**exclutions.to_dict()) == exclutions_expected_result