Call async request several times with the same AsyncClient with asyncio.run() is causing RuntimeError: Event loop is closed

[PFaurel]

When AsyncClient is used several times with an async function that's sending an http request, the first time is successful, all other attempts are failing with RuntimeError exception and "Event loop is closed" error message.

To reproduce:

import httpx

if name == 'main':

client = httpx.AsyncClient()

async def home():
    r = await client.get('https://www.example.com/')
    return r

asyncio.run(home())
asyncio.run(home())  # => RuntimeError: Event loop is closed
asyncio.run(home())  # => RuntimeError: Event loop is closed
asyncio.run(home())  # => RuntimeError: Event loop is closed

[lovelydinosaur]

So, yeah...

Don't try to share an AsyncClient across multiple event loops. That won't work, and I'd assume we probably wouldn't be able to make it work.

You either want...

async def home():
    async with httpx.AsyncClient() as client:
        r = await client.get('https://www.example.com/')
    return r

# Not sure why you'd want to do this, but at least it's not broken now...
asyncio.run(home())
asyncio.run(home())
asyncio.run(home())
asyncio.run(home())

Or more sensibly...

async def home(client):
    r = await client.get('https://www.example.com/')
    return r

async def main():
    # Structured correctly.
    # Single client shared across multiple requests.
    async with httpx.Client() as client:
        await home(client)
        await home(client)
        await home(client)
        await home(client)

asyncio.run(main())

[lovelydinosaur]

Punted this to a discussion.

If someone thinks we should either have some different behaviour or different documentation here, then let's discuss that, and then consider opening an issue.