code: def get_gravatar(email, size=80, rating='g', default=None,
                   protocol=PROTOCOL):
      
      gravatar_protocols = {'http': 'http://www',
                            'https': 'https://secure'}
      url = '%s.gravatar.com/avatar/%s' % (
          gravatar_protocols[protocol],
          md5(email.strip().lower().encode('utf-8')).hexdigest())
      options = {'s': size, 'r': rating}
      if default:
          options['d'] = default
  
      url = '%s?%s' % (url, urlencode(options))
      return url.replace('&', '&amp;')
docs: Return url for a Gravatar.