Question

I'm attempting to integrate a tqdm progress bar to monitor POST requests generated with aiohttp in Python 3.5. I have a working progress bar but can't seem to gather results using as_completed(). Pointers gratefully received.

Examples I've found suggest using the following pattern, which is incompatible with Python 3.5 async def definitions:

for f in tqdm.tqdm(asyncio.as_completed(tasks), total=len(coros)):
    yield from f

Working (albeit redacted) async code without the progress bar:

def async_classify(records):

    async def fetch(session, name, sequence):
        url = 'https://app.example.com/api/v0/search'
        payload = {'sequence': str(sequence)}
        async with session.post(url, data=payload) as response:
            return name, await response.json()

    async def loop():
        auth = aiohttp.BasicAuth(api_key)
        conn = aiohttp.TCPConnector(limit=100)
        with aiohttp.ClientSession(auth=auth, connector=conn) as session:
            tasks = [fetch(session, record.id, record.seq) for record in records]
            responses = await asyncio.gather(*tasks)    
        return OrderedDict(responses)

This is my unsuccessful attempt at modifying loop():

async def loop():
    auth = aiohttp.BasicAuth(api_key)
    conn = aiohttp.TCPConnector(limit=100)
    with aiohttp.ClientSession(auth=auth, connector=conn) as session:
        tasks = [fetch(session, record.id, record.seq) for record in records]
        for f in tqdm.tqdm(asyncio.as_completed(tasks), total=len(tasks)):
            await f
        responses = await asyncio.gather(f)
        print(responses)

Answer 1

await f会返回单个响应。为什么你将已完成的Future传递给asyncio.gather(f)还不清楚。

尝试：

responses = []
for f in tqdm.tqdm(asyncio.as_completed(tasks), total=len(tasks)):
    responses.append(await f)

Python 3.6实现PEP 530 -- Asynchronous Comprehensions：

responses = [await f
             for f in tqdm.tqdm(asyncio.as_completed(tasks), total=len(tasks))]

现在可以在async def个函数中使用。

asyncio aiohttp progress bar with tqdm

1 个答案: