auditable.py

def setup_audit(cls, level):
    # some code
    print(cls, level)


class AuditMeta(type):
    def __new__(mcs, name, bases, attrs, **kwargs):
        cls = super().__new__(mcs, name, bases, attrs)
        level = kwargs.get('level', 0)
        setup_audit(cls, level)
        return cls


class Base(metaclass=AuditMeta):
    pass


class Silent(Base):
    pass


class Auditable(Base, level=1):
    pass