def __new__(cls, name, bases, attrs):
new_cls = type.__new__(cls, name, bases, attrs)
if name in ("Model", "NewBase"):
return new_cls
mapper_class = getattr(new_cls, "Mapper", None) or getattr(new_cls, "Meta", None)
bases = []
if mapper_class is not None:
bases.append(mapper_class)
if not isinstance(mapper_class, new_cls.mapper_class):
bases.append(new_cls.mapper_class)
NewMapper = type("{}Mapper".format(new_cls.__name__), tuple(bases), {})
NewMapper(new_cls)
for k in to_tuple(mapper_registry[new_cls].pk):
setattr(new_cls, k, None)
return new_cls
def __hash__(self):
if not all(to_tuple(self._get_pk())):
raise TypeError("Model instances without primary key value are unhashable")
return hash(self._get_pk())
