Qt for Python (PySide/Shiboken)

It's ok with QImage, this what I wanna do im = QImage("a file") for x in range(im.width()): for y in range(im.height()): if im.pixelColor(x,y).alpha(): # do nothing if transparent im.setPixelColor(x, y, QColor("red"))I wonder if there's a more efficient way to do it ?