mul_threads.py

import threading
import urllib2
import time


def worker(num):
    """thread worker function"""
    response = urllib2.urlopen('http://python.org/')
    print 'Worker: %s' % num
    return

# Start time.
start_time = time.time()

# Create threads
threads = []
for i in range(20):
    t = threading.Thread(target=worker, args=(i,))
    threads.append(t)
    t.start()

# Wait all the threads to finish.
for t in threads:
    t.join()

# Print the elapsed time.
elapsed_time = time.time() - start_time
print(elapsed_time)