How to use simple Thread in Python

Already In previous post you will have read about thread (how to use thread in Pygtk (python)) . So theoretically thread is nothing but a task which works independently.

A single computer running several programs (seemingly) simultaneously. This is done by clever and frequent switching between the execution states of each program. For example, the print spooler on your PC may be printing pages from one document while you are editing another document in your word processor. 

Above was theoretical knowledge now we will see practically programming means how to use simple thread and how to use multiple threading using python.

Some Important point about multithreading for your knowledge

• Multiple threads within a process share the same data space with the main thread and can therefore share information or communicate with each other more easily than if they were separate processes.

• Threads sometimes called light-weight processes and they do not require much memory overhead; they care cheaper than processes.

• It can temporarily be put on hold (also known as sleeping) while other threads are running - this is called yielding.

• No one can stop threading once it started until completed. Only you can hold that thread as a sleeping, waiting or busy in some task.

 Example:
 

#!/usr/bin/python

import thread
import time

# Define a function for the thread
def check_time( threadName, delay):
   count = 0
   while count < 5:
      time.sleep(delay)
      count += 1
      print "%s: %s" % ( threadName, time.ctime(time.time()) )

# Create two threads as follows
try:
   thread.start_new_thread(check_time, ("Thread-1", 2, ) )
   thread.start_new_thread(check_time, ("Thread-2", 4, ) )
except:
   print "Error: unable to start thread"

When the above code is executed, it produces the following result: 

Thread-1: Thu Jan 22 15:42:17 2009
Thread-1: Thu Jan 22 15:42:19 2009
Thread-2: Thu Jan 22 15:42:19 2009
Thread-1: Thu Jan 22 15:42:21 2009
Thread-2: Thu Jan 22 15:42:23 2009
Thread-1: Thu Jan 22 15:42:23 2009
Thread-1: Thu Jan 22 15:42:25 2009
Thread-2: Thu Jan 22 15:42:27 2009
Thread-2: Thu Jan 22 15:42:31 2009
Thread-2: Thu Jan 22 15:42:35 2009

Thanks Guys