This returns a printable representation of the screen as a unicode
        string (which, under Python 3.x, is the same as 'str'). The end of each
        screen line is terminated by a newline.

def _unicode(self):
        '''This returns a printable representation of the screen as a unicode
        string (which, under Python 3.x, is the same as 'str'). The end of each
        screen line is terminated by a newline.'''

        return u'\n'.join ([ u''.join(c) for c in self.w ])