if __name__ == '__main__':
    # create application
    app = QApplication(sys.argv)
    app.setApplicationName('My PyQt4 QtGui Project')
    # create widget
    w = MainWindow()
    w.setWindowTitle('My PyQt4 QtGui Project')
    w.show()
    # connection
    QObject.connect(app, SIGNAL('lastWindowClosed()'), app, SLOT('quit()'))
    # execute application
    sys.exit(app.exec_())
    ############################
    open()