/Python/Django/Django pre_save get old instance

Django pre_save get old instance

@receiver(pre_save, sender=A)
def signal_product_manage_latest_version_id(sender, instance, update_fields=None, **kwargs):
    try:
        old_instance = A.objects.get(id=instance.id)
    except A.DoesNotExist:  # to handle initial object creation
        return None  # just exiting from signal
    # your code to with 'old_instance'

Source: stackoverflow.com

Similar codes

0 vote161 views1 answer
Django router multiple pk
Python Django
0 vote169 views2 answers
Generate random token or id in django
Python Django
0 vote181 views1 answer
Exception Type: AssertionError Exception Value: Expected a `Response`, `HttpResponse` or `HttpStreamingResponse` to be returned from the view, but received a `<class 'django.db.models.query.QuerySet'>`
Python Django
0 vote181 views1 answer
How to send file in django response
Python Django
0 vote175 views2 answers
Django pagination class based views
Python Django
1 vote156 views3 answers
Making ckeditor django responsive
Python Django
1 vote325 views1 answer
Check if the user is logged in django decorator
Python Django
0 vote175 views1 answer
Django today date in template
Python Django
1 vote184 views1 answer
How to use query_params in get_object djangorestframework
Python Django
0 vote187 views1 answer
Django optional path parameter
Python Django