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Simplistic Python Thread example

Date: Sept. 9, 2008  |   Modified: Oct. 20, 2008  |   Tags: concurrency, python   |   6 Comments

Here is a simple Python example using the Thread object in the threading module. 

import time
from threading import Thread

def myfunc(i):
    print "sleeping 5 sec from thread %d" % i
    time.sleep(5)
    print "finished sleeping from thread %d" % i

for i in range(10):
    t = Thread(target=myfunc, args=(i,))
    t.start()

Results:

sleeping 5 sec from thread 0
sleeping 5 sec from thread 1
sleeping 5 sec from thread 2
sleeping 5 sec from thread 3
sleeping 5 sec from thread 4
sleeping 5 sec from thread 5
sleeping 5 sec from thread 6
sleeping 5 sec from thread 7
sleeping 5 sec from thread 8
sleeping 5 sec from thread 9

...and 5 seconds later:

finished sleeping from thread 0
finished sleeping from thread 1
finished sleeping from thread 2
finished sleeping from thread 3
finished sleeping from thread 4
finished sleeping from thread 5
finished sleeping from thread 6
finished sleeping from thread 7
finished sleeping from thread 8
finished sleeping from thread 9

6 Comments — feed icon Comments feed for this post


#1 Tomek commented on 2009-05-24:

Cool ;) I like such simplistic examples. THX.

Tomek


#2 Eliot commented on 2009-05-24:

Tomek, heh, sometimes I do too.


#3 Oleg Tarasenko commented on 2009-09-10:

I also like the example.

I tuned it a little bit, so can use like a very simple load testing tool. E.g. if you need to generate few thousands of request.

import    urllib2                                                                                                                              
from threading import  Thread                                                                                       
def btl_test():                                                                                                                                 while 1:                                                                            
   page = urllib2.urlopen("example.com")

for i in range(120):                                                                                                                        
       t = Thread(target = btl_test)                                                                                                           
        t.start()

#4 Dankoozy commented on 2009-11-22:

Nice ... ssssssssssss very useful


#5 Bino commented on 2009-12-09:

Hi Elliot and all .. That realy great impact example.

Just one question, at line -->

t = Thread(target=myfunc, args=(i,))

Why there is a "comma" after "i" while there is only single paramater ? is it a must ?

Sincerely -bino-


#6 Eliot commented on 2009-12-09:

Oleg,
That looks like a cool example. Thanks!

Bino,
I gave it a quick try, and it looks like the comma is required.

The Thread object expects a tuple for the args argument. Since the operator for forming tuples is the comma and not the parentheses, a comma is required for a tuple of one item. See here for more info about that.

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