Celery Task Chain and Accessing **kwargs

Question

I have a situation similar to the one outlined here, except that instead of chaining tasks with multiple arguments, I want to chain tasks that return a dictionary with multi

Answer 1

This is my take at the problem, using an abstract task class:

from __future__ import absolute_import
from celery import Task
from myapp.tasks.celery import app   


class ChainedTask(Task):
    abstract = True    

    def __call__(self, *args, **kwargs):
        if len(args) == 1 and isinstance(args[0], dict):
            kwargs.update(args[0])
            args = ()
        return super(ChainedTask, self).__call__(*args, **kwargs)

@app.task(base=ChainedTask)
def task1(x, y):
    return {'x': x * 2, 'y': y * 2, 'z': x * y}    


@app.task(base=ChainedTask)
def task2(x, y, z):
    return {'x': x * 3, 'y': y * 3, 'z': z * 2}

You can now define and execute your chain as such:

from celery import chain

pipe = chain(task1.s(x=1, y=2) | task2.s())
pipe.apply_async()