How to call a method of an object returned from an async function without parentheses in Python?

Question

I got this function:

async def download(url):
    async with aiohttp.ClientSession() as session:
        async with session.get(url) as resp:
            if resp.status == 200:
                return resp

To get the data, I'd need to write:

text = await (await utils.download(url)).text()

How to change download so I can write like this

text = await utils.download(url).text()

without getting AttributeError: 'coroutine' object has no attribute 'text'?

You cannot. Because of how it is evaluated. – AVX-42 Apr 15 '20 at 05:34 — AVX-42, Apr 15 '20 at 05:34

Tal L · Answer 1 · 2020-04-15T06:29:17.360

0

May be this can help simplifying the usage:

async def download(url):
    async with aiohttp.ClientSession() as session:
        async with session.get(url) as resp:
            if resp.status == 200:
                return await resp.text()

Then to use it:

async def main():
    text = await download("http://python.org")

edited Apr 15 '20 at 06:29

answered Apr 15 '20 at 06:23

Tal L

342
1
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Yes, but I also want to call read() or json() or get some attribute – Dlean Jeans Apr 15 '20 at 06:29
@DleanJeans not sure that's possible as is, if I understand correctly the need. But you could tuple the results you need, if you know in advance what is needed: In download: return await resp.text(), await resp.read() In usage: text, read = await download(url) – Tal L Apr 15 '20 at 06:52

How to call a method of an object returned from an async function without parentheses in Python?

1 Answers1