Calibre CACM Recipe

import datetime
from calibre.ebooks.BeautifulSoup import Tag

class AdvancedUserRecipe1286242553(BasicNewsRecipe):
    title          = u'CACM'
    oldest_article = 7
    max_articles_per_feed = 100
    needs_subscription = True
    feeds          = [(u'CACM', u'http://cacm.acm.org/magazine.rss')]
    no_stylesheets        = True
    remove_tags = [
        dict(name='div', attrs={'class':['FeatureBox', 'ArticleComments', 'SideColumn', \
              'LeftColumn', 'RightColumn', 'SiteSearch', 'MainNavBar','more', 'SubMenu', 'inner']})
    ]
    cover_url_pattern = 'http://cacm.acm.org/magazines/%d/%d'

    def get_browser(self):
        br = BasicNewsRecipe.get_browser()
        if self.username is not None and self.password is not None:
            br.open('https://cacm.acm.org/login')
            br.select_form(nr=1)
            br['current_member[user]']   = self.username
            br['current_member[passwd]'] = self.password
            br.submit()
        return br

    def get_cover_url(self):
        now = datetime.datetime.now()

        cover_url = None
        soup = self.index_to_soup(self.cover_url_pattern % (now.year, now.month))
    print self.cover_url_pattern % (now.year, now.month)
        cover_item = soup.find('img',attrs={'alt':'magazine cover image'})
        if cover_item:
           cover_url = cover_item['src']
        return cover_url