code: def get_skype(self):
          
          skype_inst = x11.XInternAtom(self.disp, '_SKYPE_INSTANCE', True)
          if not skype_inst:
              return
          type_ret = Atom()
          format_ret = c_int()
          nitems_ret = c_ulong()
          bytes_after_ret = c_ulong()
          winp = pointer(Window())
          fail = x11.XGetWindowProperty(self.disp, self.win_root, skype_inst,
                              0, 1, False, 33, byref(type_ret), byref(format_ret),
                              byref(nitems_ret), byref(bytes_after_ret), byref(winp))
          if not fail and format_ret.value == 32 and nitems_ret.value == 1:
              return winp.contents.value
docs: Returns Skype window ID or None if Skype not running.