python3 futures module example

py3_futures_example.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Example of `futures` module in python3
"""
from __future__ import print_function
import sys
from time import time

# check version
if sys.version_info.major < 3:
    print("Please use python3")
    sys.exit(1)

from concurrent.futures import ProcessPoolExecutor, as_completed

def job(num1, num2):
    """
    worker
    """
    print("working on {}".format((num1, num2)))
    return num1 + num2

TO_DO = [[num1 for num1 in range(100)], [num2 for num2 in range(100)]]
START_TIME = time()

# synchronize version
with ProcessPoolExecutor(max_workers=None) as executor:
    print("setup executor time: {}".format(time() - START_TIME))
    for result in executor.map(job, TO_DO[0], TO_DO[1]):
        print("map result: {}".format(result))

# asynchronize version
futures = {}
with ProcessPoolExecutor(max_workers=None) as executor:
    for num1, num2 in zip(*TO_DO):
        future = executor.submit(job, num1, num2)
        futures[future] = (num1, num2)
    for future in as_completed(futures):
        try:
            data = future.result()
        except Exception as exp:
            print("exception: {}".format(exp))
        else:
            print("{}: {}".format(futures[future], data))