how to check if URL cannot be opened

[john]

Im new to python. So I was hoping someone could provide the following.
How would I go about checking if a user can be opened. For example if
user provides www.x.com, how would I check if there is such a url?
What methods would I need to invoke?

Thank you very much for your time

[Josef Meile]

Re: how to check if URL cannot be opened

Hi John,
[color=blue]
> Im new to python. So I was hoping someone could provide the following.
> How would I go about checking if a user can be opened. For example if
> user provides www.x.com, how would I check if there is such a url?
> What methods would I need to invoke?[/color]

This is the code I use with python greater than 2.3.3:

import urllib2
import socket

def checkUrl(url, timeout=5, SSL=0):
"""Checks an url for a python version greater
than 2.3.3.
"""

defTimeOut=sock et.getdefaultti meout()
socket.setdefau lttimeout(timeo ut)
found=1
try:
urllib2.urlopen (url)
except (urllib2.HTTPEr ror, urllib2.URLErro r,
socket.error, socket.sslerror ):
found=0
socket.setdefau lttimeout(defTi meOut)
return found

Please note that I use the setdefaulttimeo ut method of the module socket
because sometimes, specially if you type invalid ssl urls, the main
thread will take a long time till you see an answer. With the timeout,
it will wait for 5 seconds, then it will return. I also use the urllib2
because its urlopen method is better than the original of urllib: Some
webservers like zope, return an error page when an url isn't found; with
urllib.urlopen, this page will be considered as a normal page. On the
other hand, the urllib2.urlopen will raise an exception.

Regards,
Josef

[Josef Meile]

Re: how to check if URL cannot be opened

> This is the code I use with python greater than 2.3.3:[color=blue]
>
> import urllib2
> import socket
>
> def checkUrl(url, timeout=5, SSL=0):
> """Checks an url for a python version greater
> than 2.3.3.
> """
>
> defTimeOut=sock et.getdefaultti meout()
> socket.setdefau lttimeout(timeo ut)
> found=1
> try:
> urllib2.urlopen (url)
> except (urllib2.HTTPEr ror, urllib2.URLErro r,
> socket.error, socket.sslerror ):
> found=0
> socket.setdefau lttimeout(defTi meOut)
> return found[/color]
Ops, sorry, the SSL parameter isn't being used there, so you can delete it.