Exception handling during asyncio tasks

Hello.

In following code example objs variable will be empty (the results of all tasks will be lost), because one of the tasks raised exception. How can I come over that? For example, so that one of the tasks returns a normal answer, and the other returns just None.

Thank you.

tasks_gather = asyncio.gather(
    historical_pricing.events.Definition(universe = 'RUBONOR=',start = '2021-12-20 00:00',end = '2021-12-20 01:00').get_data_async(),
    historical_pricing.events.Definition(universe = 'RUBONOR=',start = '2021-12-20 01:00',end = '2021-12-20 02:00').get_data_async())

try:
    asyncio.get_event_loop().run_until_complete(tasks_gather)
    objs = tasks_gather.result()
except rd.errors.RDError as e:
    print("RDError code :", e.code)
    print("RDError message:", e.message)

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Accepted answers

umer.nalla

Hi @aleksandr.chernov1

The RD Python lib team have advised something like the following:

tasks_gather = asyncio.gather(historical_pricing.events.Definition(universe = 'RUBONOR=',
    start = '2021-12-20 00:00',
    end = '2021-12-20 01:00').get_data_async(),
    historical_pricing.events.Definition(universe = 'RUBONOR=',
    start = '2021-12-20 01:00',
    end = '2021-12-20 02:00').get_data_async(),
    return_exceptions=True
)
asyncio.get_event_loop().run_until_complete(tasks_gather)
good_response_1, error_2 = tasks_gather.result()
display(good_response_1.data.df)
display(error_2.message, error_2.code)

All comments

umer.nalla

Hi @aleksandr.chernov1

The RD Python lib team have advised something like the following:

tasks_gather = asyncio.gather(historical_pricing.events.Definition(universe = 'RUBONOR=',
    start = '2021-12-20 00:00',
    end = '2021-12-20 01:00').get_data_async(),
    historical_pricing.events.Definition(universe = 'RUBONOR=',
    start = '2021-12-20 01:00',
    end = '2021-12-20 02:00').get_data_async(),
    return_exceptions=True
)
asyncio.get_event_loop().run_until_complete(tasks_gather)
good_response_1, error_2 = tasks_gather.result()
display(good_response_1.data.df)
display(error_2.message, error_2.code)

umer.nalla

hi @aleksandr.chernov1

you can read more about the above technique at https://docs.python.org/3/library/asyncio-task.html#asyncio.gather

aleksandr.chernov1

Thank you!

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