Multithreading for Python Django

Question

Some functions should run asynchronously on the web server. Sending emails or data post-processing are typical use cases.

What is the best (or most pythonic) way wri

Answer 1

tomcounsell's approach works well if there are not too many incoming jobs. If many long-lasting jobs are run in short period of time, therefore spawning a lot of threads, the main process will suffer. In this case, you can use a thread pool with a coroutine,

# in my_utils.py

from concurrent.futures import ThreadPoolExecutor

MAX_THREADS = 10


def run_thread_pool():
    """
    Note that this is not a normal function, but a coroutine.
    All jobs are enqueued first before executed and there can be
    no more than 10 threads that run at any time point.
    """
    with ThreadPoolExecutor(max_workers=MAX_THREADS) as executor:
        while True:
            func, args, kwargs = yield
            executor.submit(func, *args, **kwargs)


pool_wrapper = run_thread_pool()

# Advance the coroutine to the first yield (priming)
next(pool_wrapper)

from my_utils import pool_wrapper

def job(*args, **kwargs):
    # do something

def handle(request):
    # make args and kwargs
    pool_wrapper.send((job, args, kwargs))
    # return a response