How do I parallelize a simple Python loop?

Question

This is probably a trivial question, but how do I parallelize the following loop in python?

# setup output lists
output1 = list()
output2 = list()
output3 =          


        

Answer 1

why dont you use threads, and one mutex to protect one global list?

import os
import re
import time
import sys
import thread

from threading import Thread

class thread_it(Thread):
    def __init__ (self,param):
        Thread.__init__(self)
        self.param = param
    def run(self):
        mutex.acquire()
        output.append(calc_stuff(self.param))
        mutex.release()   


threads = []
output = []
mutex = thread.allocate_lock()

for j in range(0, 10):
    current = thread_it(j * offset)
    threads.append(current)
    current.start()

for t in threads:
    t.join()

#here you have output list filled with data

keep in mind, you will be as fast as your slowest thread