concurrency - run multiple instances of python script simultaneously

Question

I am trying to create 86 instances of task.py to run simultaneously.

import sys
import subprocess

for file in range(86):
    subprocess.call([sys.executable,'task.py',str(file)+'in.csv',str(filen)+'out.csv'])

Answer 1

subprocess.call waits for command to complete. Use subprocess.Popen instead:

import sys
import subprocess

procs = []
for i in range(86):
    proc = subprocess.Popen([sys.executable, 'task.py', '{}in.csv'.format(i), '{}out.csv'.format(i)])
    procs.append(proc)

for proc in procs:
    proc.wait()