Resize a QGraphicsItem with the mouse

After put a rectangle in a QGraphicsScene and make it movable with the mouse, how could I resize it with the mouse?

If no one knows an answer, a example could be good too, I'm developing in Python using PYQt4, but the example can be in C++.

My simplified code:

Code:

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import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *
 
app = QApplication(sys.argv)
 
grview = QGraphicsView()
scene = QGraphicsScene()
scene.setSceneRect(0, 0, 512, 512)
 
scene.addPixmap(QPixmap('01.png'))
grview.setScene(scene)
 
item = QGraphicsRectItem(0, 0, 300, 150)
 
pen = QPen(Qt.darkMagenta)
pen.setWidth(4)
item.setPen(pen)
 
item.setFlag(QGraphicsItem.ItemIsMovable)
scene.addItem(item)
 
grview.fitInView(scene.sceneRect(), Qt.KeepAspectRatio)
 
grview.show()
 
sys.exit(app.exec_())

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