docs: def _get_horoscope(self, day='today'):
          """gets a horoscope from site html
  
          :param day: day for which to get horoscope. Default is 'today'
  
          :returns: dictionary of horoscope details
          """
          if not is_valid_day(day):
              raise HoroscopeException("Invalid day. Allowed days: [today|yesterday|tomorrow]" )
  
          horoscope = ''.join([str(s).strip() for s in self.tree.xpath('//*[@id="%s"]/p/text()' % day)])
  
          if day is 'yesterday':
              date = self.date_today - timedelta(days=1)
          elif day is 'today':
              date = self.date_today
          elif day is 'tomorrow':
              date = self.date_today + timedelta(days=1)
  
          return {
              'date': date.strftime("%Y-%m-%d"),
              'sunsign': self.sunsign.capitalize(),
              'horoscope': horoscope + "(c) Kelli Fox, The Astrologer, http://new.theastrologer.com",
              'meta': self._get_horoscope_meta(day),
              'credit': '(c) Kelli Fox, The Astrologer, http://new.theastrologer.com'
          }