code: def get_initials(pinyin, strict):
      
      if strict:
          _initials = _INITIALS
      else:
          _initials = _INITIALS_NOT_STRICT
  
      for i in _initials:
          if pinyin.startswith(i):
              return i
      return ''
docs: 获取单个拼音中的声母.
  
      :param pinyin: 单个拼音
      :type pinyin: unicode
      :param strict: 是否严格遵照《汉语拼音方案》来处理声母和韵母
      :return: 声母
      :rtype: unicode