PyQT - OpenGL - Timer

import sys
from OpenGL.GL import *
from OpenGL.GLU import *
from OpenGL.GLUT import *
from PyQt4.QtGui import *
from PyQt4.QtCore import *
from PyQt4.QtOpenGL import *
from PyQt4 import uic

class MyOGLWidget(QGLWidget):
    def __init__(self, parent=None):      
        QGLWidget.__init__(self, parent)
        self.spin = 0
             

    def initializeGL(self):
        print "init GL"
        glClearColor(0.0, 0.0, 0.0, 0.0);
        glShadeModel (GL_FLAT)
        self.timer = QTimer(self)
        self.timer.timeout.connect(self.spinDisplay)
        self.timer.start(40)
        print self.timer
     

    def resizeGL(self, w, h):
        print "resize: " + str(w ) + " x " +str(h)
        glViewport(0, 0, w, h);
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        glOrtho(-50.0, 50.0, -50.0, 50.0, -1.0, 1.0);

    def paintGL(self):
        print "paint GL"
        glClear (GL_COLOR_BUFFER_BIT );
        glPushMatrix()
        glRotatef(self.spin, 0, 0, 1)
        glColor3f (1.0, 1.0, 1.0);
        glRectf(-25.0, -25.0, 25.0, 25.0);
        glPopMatrix()
        glFlush();
     
    def spinDisplay(self):
        # print "spin display"
        self.spin = self.spin + 2
        self.spin = self.spin % 360
        # print self.spin
        #glutSwapBuffers()
        self.updateGL()
   
app = QApplication(sys.argv)
window = MyOGLWidget()
window.resize(300, 300)
window.setWindowTitle("Testing OpenGL in PyQT")
window.show()

sys.exit(app.exec_())