def drawRects(self, rects, rectCount=None): if rectCount is None: rectCount = len(rects) device = self.nullDevice() if device is None: return if device.mode() != QwtNullPaintDevice.NormalMode: try: QPaintEngine.drawRects(self, rects, rectCount) except TypeError: # PyQt <=4.9 QPaintEngine.drawRects(self, rects) return device.drawRects(rects, rectCount)