[FIXED] Adding a timeout to an asyncio aiohttp

Issue

I am currently using the following code to query an api for data

import asyncio

async def get_data(session, ticker):
    while True:
        try:
            async with session.get(url=f'api.exec.com') as response:
                if response.status == 200:
                    data = await response.json()
                    try:
                        df = pd.DataFrame(data)
                    except ValueError:
                        print("Data is not a valid float. Retrying...")
                else:
                    print("Received non-200 status code. Retrying...")
            await asyncio.sleep(1)  
        except Exception as e:
            print("Unable to get url {} due to {}. Retrying...".format(ticker, e.__class__))
            await asyncio.sleep(1)


async def main_loop(ticker_list):
    async with aiohttp.ClientSession() as session:
        ret = await asyncio.gather(*[get_data(session, tick) for tick in ticker_list])
        return ret

datas = ['x1', 'x2', 'x3', 'x4']
results = asyncio.run(main(datas))
print(results)

I want to add a timeout to the session.get.

If i was using a normal python request, I can just do the following

session.get(url=f'api.exec.com', timeout=5)

or

session.get(url=f'api.exec.com', timeout=(4,7))

How do I do the same thing with asyncio / aiohttp.ClientSession?

Should I be doing, where I just add timeout = 5 into the seesion.get line?

import asyncio

async def get_data(session, ticker):
    while True:
        try:
            async with session.get(url=f'api.exec.com', timeout = 5) as response:
                if response.status == 200:
                    data = await response.json()
                    try:
                        df = pd.DataFrame(data)
                    except ValueError:
                        print("Data is not a valid float. Retrying...")
                else:
                    print("Received non-200 status code. Retrying...")
            await asyncio.sleep(1)  
        except Exception as e:
            print("Unable to get url {} due to {}. Retrying...".format(ticker, e.__class__))
            await asyncio.sleep(1)


async def main_loop(ticker_list):
    async with aiohttp.ClientSession() as session:
        ret = await asyncio.gather(*[get_data(session, tick) for tick in ticker_list])
        return ret

datas = ['x1', 'x2', 'x3', 'x4']
results = asyncio.run(main(datas))
print(results)

Or should I be doing this? Where I add a timeout=aiohttp.ClientTimeout(total=5) object into the timeout?

import asyncio

async def get_data(session, ticker):
    while True:
        try:
            async with session.get(url=f'api.exec.com', timeout=aiohttp.ClientTimeout(total=5)) as response:
                if response.status == 200:
                    data = await response.json()
                    try:
                        df = pd.DataFrame(data)
                    except ValueError:
                        print("Data is not a valid float. Retrying...")
                else:
                    print("Received non-200 status code. Retrying...")
            await asyncio.sleep(1)  
        except Exception as e:
            print("Unable to get url {} due to {}. Retrying...".format(ticker, e.__class__))
            await asyncio.sleep(1)


async def main_loop(ticker_list):
    async with aiohttp.ClientSession() as session:
        ret = await asyncio.gather(*[get_data(session, tick) for tick in ticker_list])
        return ret

datas = ['x1', 'x2', 'x3', 'x4']
results = asyncio.run(main(datas))
print(results)

or like this? where I set the timeout in the main function?

import asyncio

async def get_data(session, ticker):
    while True:
        try:
            async with session.get(url=f'api.exec.com') as response:
                if response.status == 200:
                    data = await response.json()
                    try:
                        df = pd.DataFrame(data)
                    except ValueError:
                        print("Data is not a valid float. Retrying...")
                else:
                    print("Received non-200 status code. Retrying...")
            await asyncio.sleep(1)  
        except Exception as e:
            print("Unable to get url {} due to {}. Retrying...".format(ticker, e.__class__))
            await asyncio.sleep(1)


async def main_loop(ticker_list):
    timeout = aiohttp.ClientTimeout(total=5)  # Setting timeout here
    async with aiohttp.ClientSession(timeout=timeout) as session:
        ret = await asyncio.gather(*[get_data(session, tick) for tick in ticker_list])
        return ret

datas = ['x1', 'x2', 'x3', 'x4']
results = asyncio.run(main(datas))
print(results)

Solution

timeout = 5

This isn't valid according to the documentation, and won't work at all in v4.

The other 2 options you gave are correct.

The first sets the timeout for each request individually (and will override the timeout set in the ClientSession).

The second sets it in the session globally, so it automatically applies to all requests in that session (if not overriden).

Answered By - Sam Bull