You can get rid of the class variable INDEX and just use an instance variable. Like this:
Code:
def get_browser(self):
self.INDEX = 'http://www.economist.com/printedition/'+self.username
return BasicNewsRecipe.get_browser()
def get_cover_url(self):
br = self.browser
br.open(self.INDEX)
self.log('Fetching cover for issue: ')
date = self.username.replace('-', '')
cover_url = "http://media.economist.com/sites/default/files/imagecache/print-cover-full/%s_CNA400.jpg" % date
return cover_url