[FIXED] Grouping asynchronous functions to run

Issue

I have a code that outputs numbers from 1 to 10:

from asyncio import get_event_loop, gather, sleep
    
async def main(k):
    print(k)
    await sleep(1)
    
    
if __name__ == '__main__':
    list_objects = list()
    count_group = 3

    for i in range(1, 11):
        list_objects.append(i)

    list_func = [main(x) for x in list_objects]

    loop = get_event_loop()
    loop.run_until_complete(gather(
        *list_func
    ))

Output:

1 2 3 4 5 6 7 8 9 10

It is noticeable that in the example above, 10 functions are simultaneously launched at once. How can I fix the code so that the number of concurrent launched functions main() is equal to count_group? That is, immediately the output should be 123, then 456, then 789 and at the end 10.

Solution

Split your tasks into run groups and gather() each group one by one.

Example:

if __name__ == '__main__':
    count_group = 3

    list_func = [ main(x) for x in range(1,11) ]
    run_groups = [ list_func[i:i+count_group] for i in range(0, len(list_func), count_group)]
    loop = get_event_loop()

    for rg in run_groups:
        loop.run_until_complete(gather(*rg))

Answered By - vaizki