def initUI(self):

    self.statusbar = self.statusBar()
    self.statusbar.showMessage('Ready')

    menubar = self.menuBar()
    viewMenu = menubar.addMenu('View')

    viewStatAct = QAction('View statusbar', self, checkable=True)
    viewStatAct.setStatusTip('View statusbar')
    viewStatAct.setChecked(True)
    viewStatAct.triggered.connect(self.toggleMenu)

    viewMenu.addAction(viewStatAct)

    self.setGeometry(300, 300, 300, 200)
    self.setWindowTitle('Check menu')
    self.show()

def toggleMenu(self, state):

    if state:
        self.statusbar.show()
    else:
        self.statusbar.hide()