code: def load_single_dict(pinyin_dict, style='default'):
      
      if style == 'tone2':
          for k, v in pinyin_dict.items():
              v = _replace_tone2_style_dict_to_default(v)
              PINYIN_DICT[k] = v
      else:
          PINYIN_DICT.update(pinyin_dict)
  
      mmseg.retrain(mmseg.seg)
docs: 载入用户自定义的单字拼音库
  
      :param pinyin_dict: 单字拼音库。比如： ``{0x963F: u"ā,ē"}``
      :param style: pinyin_dict 参数值的拼音库风格. 支持 'default', 'tone2'
      :type pinyin_dict: dict