code: def download(url, filename):
      
      logger.info("Downloading %s", url)
      request = urllib2.Request(url)
      request.add_header('User-Agent',
                         'caelum/0.1 +https://github.com/nrcharles/caelum')
      opener = urllib2.build_opener()
      local_file = open(filename, 'w')
      local_file.write(opener.open(request).read())
      local_file.close()
docs: download and extract file.