Python multiprocessing module evolution

skeleton2.py

#!/usr/bin/env python2
'''
skeleton for parallel python 2 scripts

Marco Galardini 2015
GPL v3.0
'''
import sys
from multiprocessing.queues import Queue
import multiprocessing
import time

class Worker(object):
    def __init__(self, number):
        self.number = number
 
    def __call__(self):
        print('worker number %d'%self.number)
        time.sleep(5)
        return True

class Consumer(multiprocessing.Process):
    def __init__(self, 
                 task_queue = multiprocessing.Queue(),
                 result_queue = multiprocessing.Queue()):
        multiprocessing.Process.__init__(self)
        self.task_queue = task_queue
        self.result_queue = result_queue

    def run(self):
        while True:
            next_task = self.task_queue.get()
            time.sleep(0.01)
            if next_task is None:
                # Poison pill means we should exit
                break
            answer = next_task()
            self.result_queue.put(answer)
        return

class MultiProcess(object):
    '''
    Class MultiProcess
    An object that can perform multiprocesses
    '''
    def __init__(self,ncpus=1):
        self.ncpus = int(ncpus)
        # Parallelization
        self._parallel = None
        self._paralleltasks = Queue()
        self._parallelresults = Queue()
    
    def init(self):
        self._parallel = [Consumer(self._paralleltasks,self._parallelresults)
                          for x in range(self.ncpus)]
        for consumer in self._parallel:
            consumer.start()
            
    def add_poison(self):
        for consumer in self._parallel:
            self._paralleltasks.put(None)

    def is_terminated(self):
        for consumer in self._parallel:
            if consumer.is_alive():
                return False
        return True

    def kill(self):
        for consumer in self._parallel:
            consumer.terminate()
            
    def work(self):
        self.init()
    
        for i in range(10):
            obj = Worker(i)
            self._paralleltasks.put(obj)
            
        # Poison pill to stop the workers
        self.add_poison()
        
        while True:
            while not self._parallelresults.empty():
                result = self._parallelresults.get() 
            if self.is_terminated():
                break
            
            time.sleep(0.1)
            
        # Get the last messages
        while not self._parallelresults.empty():
            result = self._parallelresults.get()
            
        self.kill()
        
        return True

MultiProcess(int(sys.argv[1])).work()

skeleton3.py

#!/usr/bin/env python3
'''
skeleton for parallel python 3 scripts

Marco Galardini 2015
GPL v3.0
'''
from multiprocessing import Pool
import time
import sys

def work(x):
    print('worker number %d'%x)
    time.sleep(5)

if __name__ == '__main__':
    with Pool(int(sys.argv[1])) as p:
        p.map(work, range(10))