gistfile1.py

def add_concurrent_options(parser, prefer_threads=False):
    # Adds relevant options to parser
    parser.add_argument("--workers", choices=("threads", "processes"), default="threads" if prefer_threads else "processes",
                        help="Select if concurrency is done using threads or processes [%(default)s]")
    parser.add_argument("--single", action="store_true", help="Uses a single thread for concurrency.  This makes debugging a lot easier")

import multiprocessing
def get_concurrent_executor(options):
    # Gets a suitable executor
    if options.workers=="threads" or options.single:
        workers=multiprocessing.cpu_count() if not options.single else 1
        return futures.ThreadPoolExecutor(max_workers=workers)
    return futures.ProcessPoolExecutor()