docs: def get_addr(iface='lo0', iface_type='link'):
      """
          获取网络接口 ``iface`` 的 ``mac``
  
      - 如果系统类型为 ``mac``, 使用 ``psutil``
      - 其他使用 ``socket``
  
      :param iface: ``网络接口``
      :type iface: str
      :return: ``mac地址/空``
      :rtype: str/None
      """
      if platform.system() in ['Darwin', 'Linux']:
          if iface_type == 'link':
              _AF_FAMILY = psutil.AF_LINK
          elif iface_type in ['inet', 'inet6']:
              _AF_FAMILY = getattr(socket, 'AF_{}'.format(iface_type.upper()))
          else:
              raise SystemError('Not valid address FAMILY')
      else:
          raise SystemExit('Unsupported System. Only Mac/Linux Supported')
  
      addrs = psutil.net_if_addrs()
      for n in addrs[iface]:
          if n.family == _AF_FAMILY:
              return n.address