How to login to webpage with cookies and user-agent?

I am trying to log to certain server and download pictures from there programatically. I know login and I was able to get which variables are username and password. I was also able to download pictures which needed no password with this code.

Web page keeps telling me my user agent is unsupported, so I assume I am setting user agent incorrectly.

It needs cookies and user-agent. I know how to login to pages with cookies but I do not know how to add User-agent parameter to HTTP request in Python (and check if it was correctly added).

I am building standard url opener. I am using this code :

def login(_url, _name, _password):
    if 1:
        opener = urllib2.build_opener(urllib2.HTTPCookieProcessor())
        opener.addheaders = {("User-Agent", "Mozilla/5.0 (Windows NT 6.1; rv:5.0) Gecko/20100101 Firefox/5.开发者_开发问答0")}
        urllib2.install_opener(opener)
        #
        # login parameters
        # PRE:
        #     1] addons.mozilla.org/en-US/firefox/addon/live-http-headers/
        #    2] _url is first line, sometimes it ends with do-submit, php...
        #    3] _name and _password is content
        # SOURCE:
        # http://www.oooff.com/php-scripts/basic-curl-form-filling-tutorial/php-newbie-form-fill-tutorial.php
        #
    else:
        #
        # i tried even mechanize
        # but I do not know how to set it either
        #
        cookies = mechanize.CookieJar()
        opener = mechanize.build_opener(mechanize.HTTPCookieProcessor(cookies))

    params = urllib.urlencode(dict(login=_name, password=_password))
    f = opener.open(_url, params)
    data = f.read()
    f.close()
    return opener

I tried to move adheaders to differend places, but it did not help. Maybe it can be done with mechanize but I am not sure how.

Thanks for help. :)

---

The python docs page has this format for building openers using square brackets. You are passing it as {(...)}

import urllib2
opener = urllib2.build_opener()
opener.addheaders = [('User-agent', 'Mozilla/5.0')]
opener.open('http://www.example.com/')