Python pool multi thread/process example

gistfile1.py

import time, random

PROCESS = True
JOB_POOL_SIZE = 10
DATABASE_POOL_SIZE = 5

def apply_job(arg):
    r = random.random() *10
    time.sleep(r)
    return (arg, r)
    
def db_callback(arg):
    print "DbCallback", arg

def update_db(arg):
    time.sleep(1)
    return arg

if __name__ == '__main__':
    print "Creating Pool"
    if PROCESS:
        import multiprocessing as mult
        pool = mult.Pool(processes=JOB_POOL_SIZE)
        database_pool = mult.Pool(processes=DATABASE_POOL_SIZE)
    else:
        from multiprocessing.pool import ThreadPool
        pool = ThreadPool(processes=JOB_POOL_SIZE)
        database_pool = ThreadPool(processes=DATABASE_POOL_SIZE)
    
    jobs= range(1, 50)

    for res in pool.imap_unordered(apply_job, jobs):
    #for res in pool.imap(apply_job, jobs): if you need the result to be ordered for whatever reason
        database_pool.apply_async(update_db, args=[res], callback=db_callback)