import copy class ClonableMixin(object): def clone(self): """Return an identical copy of the instance with a new ID.""" if not self.pk: raise ValueError('Instance must be saved before it can be cloned.') duplicate = copy.copy(self) # Setting pk to None tricks Django into thinking this is a new object. duplicate.pk = None duplicate.save() # ... but the trick loses all ManyToMany relations. for field in self._meta.many_to_many: source = getattr(self, field.attname) destination = getattr(duplicate, field.attname) for item in source.all(): destination.add(item) return duplicate