How to test a URL request in a "while True" loop

[Brian D]

I'm actually using mechanize, but that's too complicated for testing
purposes. Instead, I've simulated in a urllib2 sample below an attempt
to test for a valid URL request.

I'm attempting to craft a loop that will trap failed attempts to
request a URL (in cases where the connection intermittently fails),
and repeat the URL request a few times, stopping after the Nth attempt
is tried.

Specifically, in the example below, a bad URL is requested for the
first and second iterations. On the third iteration, a valid URL will
be requested. The valid URL will be requested until the 5th iteration,
when a break statement is reached to stop the loop. The 5th iteration
also restores the values to their original state for ease of repeat
execution.

What I don't understand is how to test for a valid URL request, and
then jump out of the "while True" loop to proceed to another line of
code below the loop. There's probably faulty logic in this approach. I
imagine I should wrap the URL request in a function, and perhaps store
the response as a global variable.

This is really more of a basic Python logic question than it is a
urllib2 question.

Any suggestions?

Thanks,
Brian


import urllib2
user_agent = 'Windows; U; Windows NT 5.1; en-US; rv:1.9.0.10) Gecko/
2009042316 Firefox/3.0.10'
user_agent = 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:
1.9.0.16) ' \
             'Gecko/2009120208 Firefox/3.0.16 (.NET CLR 3.5.30729)'
headers={'User-Agent':user_agent,}
url = 'http://this is a bad url'
count = 0
while True:
	count += 1
	try:
		print 'attempt ' + str(count)
		request = urllib2.Request(url, None, headers)
		response = urllib2.urlopen(request)
		if response:
			print 'True response.'
		if count == 5:
			count = 0
			url = 'http://this is a bad url'
			print 'How do I get out of this thing?'
			break
	except:
		print 'fail ' + str(count)
		if count == 3:
			url = 'http://www.google.com'