How do I prevent Python's urllib(2) from following a redirect

Question

I am currently trying to log into a site using Python however the site seems to be sending a cookie and a redirect statement on the same page. Python seems to be following that redirect thus preventing me from reading the cookie send by the login page. How do I prevent Python's urllib (or urllib2) urlopen from following the redirect?

Answer 1

urllib2.urlopen calls build_opener() which uses this list of handler classes:

handlers = [ProxyHandler, UnknownHandler, HTTPHandler,
HTTPDefaultErrorHandler, HTTPRedirectHandler,
FTPHandler, FileHandler, HTTPErrorProcessor]

You could try calling urllib2.build_opener(handlers) yourself with a list that omits HTTPRedirectHandler, then call the open() method on the result to open your URL. If you really dislike redirects, you could even call urllib2.install_opener(opener) to your own non-redirecting opener.

It sounds like your real problem is that urllib2 isn't doing cookies the way you'd like. See also How to use Python to login to a webpage and retrieve cookies for later usage?

Answer 2

This question was asked before here.

EDIT: If you have to deal with quirky web applications you should probably try out mechanize. It's a great library that simulates a web browser. You can control redirecting, cookies, page refreshes... If the website doesn't rely [heavily] on JavaScript, you'll get along very nicely with mechanize.

Answer 3

You could do a couple of things:

1. Build your own HTTPRedirectHandler that intercepts each redirect
2. Create an instance of HTTPCookieProcessor and install that opener so that you have access to the cookiejar.

This is a quick little thing that shows both

import urllib2

redirect_handler = urllib2.HTTPRedirectHandler()

class MyHTTPRedirectHandler(urllib2.HTTPRedirectHandler):
    def http_error_302(self, req, fp, code, msg, headers):
        print "Cookie Manip Right Here"
        return urllib2.HTTPRedirectHandler.http_error_302(self, req, fp, code, msg, headers)

    http_error_301 = http_error_303 = http_error_307 = http_error_302

cookieprocessor = urllib2.HTTPCookieProcessor()

opener = urllib2.build_opener(MyHTTPRedirectHandler, cookieprocessor)
urllib2.install_opener(opener)

response =urllib2.urlopen("WHEREEVER")
print response.read()

print cookieprocessor.cookiejar