JournalMixin for django Model

models.py

class JournalMixin(object):
    def __init__(self, *args, **kwargs):
        super(JournalMixin, self).__init__(*args, **kwargs)
        logger.error('__Init__ save journal')
        old_save = getattr(self, 'save', None)
        if old_save is not None:
            def new_save(self, *args, **kwargs):
                logger.error('new save journal')
                try:
                    old_save.im_func(self, *args, **kwargs)
                    journal = {
                        'trace_id': self.trace_id,
                        'level': logging.DEBUG}
                    payload = serializers.serialize('json', [self])
                    payload = json.loads(payload[1:-1])
                    payload = {'event': 'save', 'status': 'OK',
                               'instance': payload}
                    journal.update({'payload': payload})
                    journal = Journal(**journal)
                    journal.save()
                except Exception as e:
                    trace_id = getattr(self, 'trace_id', None)
                    if trace_id is None:
                        trace_id = getattr(self, 'id', None)
                    if trace_id is None:
                        trace_id = 'Unknown'
                    journal = {'trace_id': trace_id, 'level': logging.ERROR}
                    payload = serializers.serialize('json', [self])
                    payload = json.loads(payload[1:-1])
                    payload = {'event': 'save', 'status': 'FAIL',
                               'instance': payload}
                    journal.update({'payload': payload})
                    journal = Journal(**journal)
                    journal.save()
                    raise e

            new_save = types.MethodType(new_save, self, self.__class__)
            setattr(self, 'save', new_save)