How can you catch a custom exception from Celery worker, or stop it being prefixed with `celery.backends.base`?

Question

My Celery task raises a custom exception NonTransientProcessingError, which is then caught by AsyncResult.get(). Tasks.py:

class NonTra         


        

Answer 1

import celery
from celery import shared_task


class NonTransientProcessingError(Exception):
    pass


class CeleryTask(celery.Task):

    def on_failure(self, exc, task_id, args, kwargs, einfo):
        if isinstance(exc, NonTransientProcessingError):
            """
            deal with NonTransientProcessingError
            """
            pass

    def run(self, *args, **kwargs):
        pass


@shared_task(base=CeleryTask)
def add(x, y):
    raise NonTransientProcessingError

Use a base Task with on_failure callback to catch custom exception.