Using httpx with multiprocessing

httpx_multiprocessing.py

import asyncio
import multiprocessing

import httpx


class Publisher:
    def __init__(self):
        # NOTE(kgriffs): Explicitly manage the client so we can use the
        #   connection pool. This class could be made into a singleton
        #   or something to make it easy to reuse across modules without
        #   having to pass the instance around.
        self._client = httpx.AsyncClient()

    async def echo(self, number):
        r = await self._client.get('https://httpbin.org/anything', headers={'X-Publisher': str(number)})
        return r.json()

    async def close(self):
        await self._client.aclose()


async def main_async(number):
    publisher = Publisher()

    try:
        result = await publisher.echo(number)
        print(result)
    finally:
        # NOTE(kgriffs): Not strictly necessary since the process is
        #   about to exit and the OS should clean up the resources
        #   for us.
        await publisher.close()


def main(number):
    print(f'Starting processor: {number}')
    asyncio.run(main_async(number))


if __name__ == "__main__":
    number_to_process = range(1, 10)
    with multiprocessing.Pool() as pool:
        pool.map(main, number_to_process)