python threading example

thread_test.py

from itertools import groupby
from threading import Thread
from random import randint
from time import sleep

# see http://stackoverflow.com/questions/29291270/threading-in-python-processing-multiple-large-files-concurrently
for key, partition in groupby(range(1, 50), lambda k: k//10):
  threads = []
  for idx in list(partition):
    thread_name = 'thread-%d' % idx
    t = Thread(name=thread_name, target=sleep, args=(randint(1, 5),))
    threads.append(t)
    print 'Starting %s' % t.getName()
    t.start()

  for t in threads:
    print 'Joining %s' % t.getName()
    t.join()

  print 'Joined the first group of %s' % map(lambda t: t.getName(), threads)