How to find out whether computer is connected to internet?

Question

How to find out whether computer is connected to internet in python?

score 16 · Answer 1 · answered Aug 28 '09 at 12:11

16

If you have python2.6 you can set a timeout. Otherwise the connection might block for a long time.

try:
    urllib2.urlopen("http://example.com", timeout=2)
except urllib2.URLError:
    # There is no connection

answered Aug 28 '09 at 12:11

Nadia Alramli

1

+1 for the timeout. As Gamecat said, it could also mean that example.com is down :-) – Vinay Sajip Aug 28 '09 at 12:17
11

@Vinay, that's right. Maybe he should try google.com. If google was down. Then I guess there is no internet ;) – Nadia Alramli Aug 28 '09 at 12:19
1

you can set a timeout in 2.5 as well using import socket; socket.setdefaulttimeout(); – tgray Aug 28 '09 at 14:45

score 7 · Answer 2 · answered Aug 28 '09 at 12:06

7

Try

import urllib
file = urllib.urlopen("http://stackoverflow.com/")
html = file.read()

and see if that works, or if it throws an exception. Even if you don't use the exact code, you should get the idea.

answered Aug 28 '09 at 12:06

Vinay Sajip

2

Lol, it only gives a false negative if SO is down ;-). Better check a couple of sites and assume connection if at least one is up. – Toon Krijthe Aug 28 '09 at 12:09
It was just an illustration - use any site you want! – Vinay Sajip Aug 28 '09 at 12:15
it can also fail if a proxy server is running. – Nick Dandoulakis Aug 28 '09 at 12:18
I think you mean "a proxy server is configured but not running". – Vinay Sajip Aug 28 '09 at 12:21
Plenty of tricky failure modes. I know an environment that will popup a dialog box warning you that the connection attempt has been logged, and please enter username+password to connect to stackoverflow.com. That's a system-modal dialog I think. – MSalters Aug 28 '09 at 15:29

2 Answers2