Python 2.7 如何解决加载图像时的错误

当我尝试执行此代码时。。图像未显示，程序终止。。 好心帮忙

def loadImage(self):
    filename = QtWidgets.QFileDialog.getOpenFileName(None,"Select Image",'', "Image Files(*.jpg);;All Files(*)")
    if filename:
        print(filename)
        self.file = filename
        pixmap = QtGui.QPixmap(filename) 
        pixmap =  pixmap.scaled(self.imageLb1.width(),self.imageLb1.width()
                               ,QtCore.Qt.KeepAspectRatio)
        self.imageLb1.setPixmap(pixmap)
        self.imageLb1.setAlignment(QtCore.Qt.AlignCenter)

如有任何建议，将不胜感激