Celery: How to ignore task result in chord or chain?

There is a built-in functionality to ignore result in chaining and others - immutable subtask. You can use .si() shortcut instead of .s() or .subtask(immutable=True)

More details here: http://docs.celeryproject.org/en/master/userguide/canvas.html#immutability

One possible solution has already posted, but I'd like to add further clarification and an alternate solution (and in some cases a superior one).

The error you're seeing, which indicates that your task's signature needs to take into account a second parameter, is due to the fact that when calling tasks in a chain, Celery automatically pushes each tasks result as the first parameter of the following task.

From the docs:

Tasks can be linked together, which in practice means adding a callback task:

>>> res = add.apply_async((2, 2), link=mul.s(16))>>> res.get()4

The linked task will be applied with the result of its parent task as the first argument

Therefore, in your case, you could rewrite your task like this:

@celery.taskdef tprint(result, word):    print word

If you're not going to do anything with the result, you may as well ignore it, by changing the decorator thus:

@celery.task(ignore_result=True)

And then you won't have to change your task signature.

Sorry, that last point needs further research.

You can try doing something like this.Instead of having a single parameter for function tprint you can have 2 parameters

def tprint(word, x=None):    print word

then

chain(tprint.s('a', 0) | tprint.s('b'))()