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Python - parallel commands

How to execute multiple python commands in parallel in a python script? As a simple example, I have several sleep commands:

time.sleep(4)
time.sleep(6)
time.sleep(8)

I want all of the above to be done in parallel. I expect the control to return when 8 seconds have passed (which is the maximum number of all berths above). Real teams will be different, but you want to get the idea above.

In bash, I could do simply:

sleep 4 &
pid1=$!
sleep 6 &
pid2=$!
sleep 8 &
pid3=$!
wait $pid1 $pid2 $pid3

Thank.

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3 answers

One simple example: using multiprocessing:

import multiprocessing as mp
import time

pool = mp.Pool(3)
results = pool.map(time.sleep, [4, 6, 8] )

, . GIL ( cpython), , python ( cpython ). , , , , ( - threading).

:

+10

threading. - :

import time,threading

def mySleep( sec ):
    time.sleep( sec )
t1 = threading.Thread( target=mySleep, args=(4,) )
t2 = threading.Thread( target=mySleep, args=(6,) )
t3 = threading.Thread( target=mySleep, args=(8,) )
t1.start()
t2.start()
t3.start()

# All threads running in parallel, now we wait
t1.join()
t2.join()
t3.join()
+6
from threading import Thread

threads = [Thread(target=time.sleep, args=(secs,)) for secs in (4,6,8)]
for t in threads: t.start()
for t in threads: t.join()
print 'all threads done!'
+4

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