from cbs import BaseSettings, env


...
# For env settings with a DJANGO_ prefix
denv = env['DJANGO_']

class Settings(BaseSettings):

    DEBUG = denv.bool(True)  # Controlled by DJANGO_DEBUG env var

    DEFAULT_DATABASE = denv.dburl('sqlite://db.sqlite')

    def DATABASES(self):
        return {
            'default': self.DEFAULT_DATABASE,
        }


class ProdSettings(Settings):
    DEBUG = False

    @env
    def STATIC_ROOT(self):
        raise ValueError("Must set STATIC_ROOT!")

__getattr__, __dir__ = BaseSettings.use()

# Run default Settings
$ ./manage.py test

# Run ProdSettings
$ DJANGO_MODE=prod ./manage.py test