class MyClass:
    __slots__ = "attr"  # should be an iterable

    def __init__(self):
        pass

from django.apps import AppConfig


class TweetsConfig(AppConfig):
    default_auto_field = 'django.db.models.BigAutoField'
    name = 'tweets'

class MyClass:
    __slots__ = ("attr", )

    def __init__(self):
        pass