'Print out the readings for  the discourse (or a single sentence).'

def _show_readings(self, sentence=None):

    if (sentence is not None):
        print(("The    sentence    '%s'    has    these    readings:" % sentence))
        for r in [str(reading) for reading in self._get_readings(sentence)]:
            print(('                %s' % r))
    else:
        for sid in sorted(self._readings):
            print()
            print(('%s    readings:' % sid))
            print()
            for rid in sorted(self._readings[sid]):
                lf = self._readings[sid][rid]
                print(('%s:    %s' % (rid, lf.normalize())))
