Get async celery results from nested subtasks as they complete

results.py

from tasks import task1

def get_results(queries):
    query_procs = task1.delay(queries).get().join()
    results = []
    for query_proc in query_procs:
        # while the following iterate() is happening, the other query_procs are ignored.
        # ideas on iterating over all of them at once?
        for result in query_proc.iterate(): 
            yield result

for result in get_results(['a','b','c']):
    print result

tasks.py

from celery.task import task,TaskSet
import time
import random

@task
def task1(queries):
    return TaskSet(task2.subtask((query, )) for query in queries).apply_async()
                                                                                                   
@task
def task2(query):
   return TaskSet(task3.subtask(query) for _ in xrange(20)).apply_async()

@task
def task3(query):
    seconds = random.randint(0,10)
    time.sleep(seconds)
    return query,seconds