Exception handling on asyncronously HTTP-requests in Python 3.x - python-3.x

Question

I'm trying to handle an asynchronous HTTP request. I call the async_provider() function from another module and with the resulting response.text() I perform subsequent tasks.
It only works if all requests are successful. But I can't handle any exceptions for failed requests (whatever the reason for the exception). Thank you for your help.
Here is the relevant part of the code:
import asyncio
import aiohttp
# i call this function from another module
def async_provider():
list_a, list_b = asyncio.run(main())
return list_a, list_b
async def fetch(session, url):
# session.post request cases
if url == "http://...1":
referer = "http://...referer"
user_agent = (
"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_4) "
"AppleWebKit/605.1.15 (KHTML, like Gecko) "
"Version/12.1 Safari/605.1.15"
)
payload = {'key1': 'value1', 'key2': 'value2'}
async with session.post(
url, data=payload, headers={"Referer": referer, "User-Agent": user_agent}
) as response:
if response.status != 200:
response.raise_for_status()
return await response.text()
# session.get request cases
else:
async with session.get(url) as response:
if response.status != 200:
response.raise_for_status()
return await response.text()
async def fetch_all(session, urls):
results = await asyncio.gather(
*[asyncio.create_task(fetch(session, url)) for url in urls]
)
return results
async def main():
urls = ["http://...1", "http://...2", "http://...3"]
async with aiohttp.ClientSession() as session:
response_text_1, response_text_2, response_text_3 = await fetch_all(
session, urls
)
# some task with response text
Any exception breaks all requests

Answer 1

Check "return_exceptions" flag on gather.
results = await asyncio.gather(
*[asyncio.create_task(fetch(session, url)) for url in urls],
return_exceptions=True
)
It will return you list of finished tasks. You can then use their Task.result() or
Task.exception() methods to reraise or check if there was exception.