def grouper(results):    while True:        key = yield        results[key] = yield from averager()def main(data):    results = {}    group = grouper(results)    next(group)    for key, values in data.items():        group.send(key)        for value in values:            group.send(value)        group.send(None)    group.close() # just to highlight that grouper is still an active generator    report(results)