def get_historical_prices(self, start_date, end_date):
        """
        Get historical prices for the given ticker symbol.
        Date format is 'YYYYMMDD'
    
        Returns a nested list.
        """
        url = 'http://ichart.yahoo.com/table.csv?s=%s&' % self.symbol + \
              'd=%s&' % str(int(end_date[4:6]) - 1) + \
              'e=%s&' % str(int(end_date[6:8])) + \
              'f=%s&' % str(int(end_date[0:4])) + \
              'g=d&' + \
              'a=%s&' % str(int(start_date[4:6]) - 1) + \
              'b=%s&' % str(int(start_date[6:8])) + \
              'c=%s&' % str(int(start_date[0:4])) + \
              'ignore=.csv'
        days = urllib.urlopen(url).readlines()
        data = [day[:-2].split(',') for day in days]
        return data

        Get historical prices for the given ticker symbol.
        Date format is 'YYYYMMDD'
    
        Returns a nested list.
        
recipes/Python/577989_Yahoo_Stock_Information/recipe-577989.py