Intermediate Python P. 26 Asyncio

우린 concurrency 를 얘기하면서 parallelism 을 떠올린다. 하지만 그건 서로 다른 의미입니다. 전자는 여러 thread가 번갈아가며 처리된다는 뜻이고, 후자는 복수의 thread가 동시에 같은 시간에 병행처리된다는 뜻입니다. 여기 토픽인 asyncio는 후자 보다는 전자에 가까운 의미입니다.
import asyncio
#docs.python.org/3.6/library/asyncio-eventloop.html
async def find_divisibles(inrange, div_by):
print("finding nums in range {} divisible by {}".format(inrange, div_by))
located = []
for i in range(inrange):
if i % div_by == 0:
located.append(i)
if i % 500000 == 0:
await asyncio.sleep(0.0001)
print("Done w/ nums in range {} divisible by {}".format(inrange, div_by))
return located
#Next, let's add a main() function, which will serve as our main block of code that executes these functions:
async def main(): #usual mistake2 - without async, you gonna get syntaxError
divs1 = loop.create_task(find_divisibles(508000, 34113))
divs2 = loop.create_task(find_divisibles(100052, 3210))
divs3 = loop.create_task(find_divisibles(500, 3))
await asyncio.wait([divs1,divs2,divs3]) #usual mistake1 - without await, task destroyed and is pending
return divs1, divs2, divs3
#Finally, let's just run the main function:
if __name__ == '__main__':
try:
loop = asyncio.get_event_loop() #initialize loop for us
loop.set_debug(1)
d1, d2, d3 = loop.run_until_complete(main())
print(d1.result())
except Exception as e:
pass
finally:
loop.close()


원본 비디오: https://www.youtube.com/watch?v=BI0asZuqFXM&list=PLQVvvaa0QuDfju7ADVp5W1GF9jVhjbX-_&index=27