how to make qmenu item checkable pyqt4 python

like this:

from PyQt4 import QtGui

app = QtGui.QApplication([])

w = QtGui.QMainWindow()
menu = QtGui.QMenu("menu", w)

menu.addAction(QtGui.QAction('50%', menu, checkable=True))
menu.addAction(QtGui.QAction('100%', menu, checkable=True))
menu.addAction(QtGui.QAction('200%', menu, checkable=True))
menu.addAction(QtGui.QAction('300%', menu, checkable=True))
menu.addAction(QtGui.QAction('400%', menu, checkable=True))

w.menuBar().addMenu(menu)
w.show()
app.exec_()

or witht radio buttons:

from PyQt4 import QtGui

app = QtGui.QApplication([])

w = QtGui.QMainWindow()
menu = QtGui.QMenu("menu", w)
ag = QtGui.QActionGroup(w, exclusive=True)

a = ag.addAction(QtGui.QAction('50%', w, checkable=True))
menu.addAction(a)

a = ag.addAction(QtGui.QAction('100%', w, checkable=True))
menu.addAction(a)

a = ag.addAction(QtGui.QAction('200%', w, checkable=True))
menu.addAction(a)

a = ag.addAction(QtGui.QAction('300%', w, checkable=True))
menu.addAction(a)

a = ag.addAction(QtGui.QAction('400%', w, checkable=True))
menu.addAction(a)

w.menuBar().addMenu(menu)
w.show()
app.exec_()

I suggest adding a few lines to the compact first solution to show the actual use of the buttons:

from PyQt4 import QtGui, QtCore

def isChecked(): 
    """ Prints selected menu labels. """ 
    [print(action.text()) for action in menu.actions() if action.isChecked()]

app = QtGui.QApplication([])
w = QtGui.QMainWindow()
menu = QtGui.QMenu("menu", w)

menu.addAction(QtGui.QAction('50%', menu, checkable=True))
menu.addAction(QtGui.QAction('100%', menu, checkable=True))
menu.addAction(QtGui.QAction('200%', menu, checkable=True))
menu.addAction(QtGui.QAction('400%', menu, checkable=True))

menu.triggered.connect(isChecked)

w.menuBar().addMenu(menu)
w.show()
app.exec_()