Asynchronous results in Zappa

async-app.py

from zappa.async import task, get_async_response
from flask import Flask
from time import sleep, time

app = Flask(__name__)


@app.route('/bake')
def bake():
    start = time()
    baking = []
    for i in range(0, int(request.args.get('num', 3))):
        baking.append(bake_one().response_id)


    baked = {}
    bake_time = 0
    while True:
        for b in baking:
            if b in baked:
                continue
            response = get_async_response(b)
            if response is not None and response['status'] == 'complete':
                baked[b] = response['response']
                bake_time = bake_time + response['response']['time']


        if len(baked) == len(baking):
            break  # from the (while True)
        else:
            # not done baking all of the things
            sleep(1)

    elapsed = time() - start

    out = "Baked {} items in {} seconds. Baking took {} seconds.\n\n".format(
        len(baked), elapsed, bake_time)
    for response_id, result in baked.items():
        out = out + "Baked a {} in {} seconds.\n".format(
            result['what'], result['time'])

    return out


@task(capture_response=True)
def bake_one():
    bake_time = randint(1,10)
    sleep(bake_time)
    return {
        "what":  choice(['pie', 'cake', 'casserole', 'potato']),
        "time": bake_time,
    }