python - Duplicate/Archive entry in Django to another model -

i have been @ 2 days , i'm hoping can point me in right direction. trying duplicate entry in table/model model mirrored fields, creating archived version. want happen when user calls update view.

what have tried far setting pk none , trying find way move previous version mirrored/archive model. after couple of hours of research gave on path. next thought answer lie pre_save receiver can't find way access model instance save archive model.

@receiver(pre_save, sender=instrumentannual) def archive_calc_instance(sender, instance, **kwargs):      stored_id = getattr(instance, 'id', none)     e = instrumentannual.objects.filter(id = stored_id)     archive = instrumentannualarchive(e.field_name, e.another_field_name...)     archive.save() 

as far can tell should work e contains first field model.

is there can done code achieve goal or there more 'django' way solve this? i.e. sort of official archive feature?

thanks in advance.

with of @igor's comment amended solution this:

def archive_calc(self, object_id):     annual = instrumentannual.objects.get(id = object_id)     annual_archive = instrumentannualarchive()      field in annual._meta.fields:         setattr(annual_archive, field.name, getattr(annual, field.name))     annual_archive.pk = none     annual_archive.save() 

it occured me using pre_save wouldn't work listening/linked model, not view thought. placed above code in update view , called passing id in object_id.

thanks again help.