PyQt Image As Checkbox Button

button image

import sys

from PyQt4 import QtCore
from PyQt4.QtGui import *


def abu():
    global button, checked

    checked = not checked
    ic = icon1 if checked else icon2
    button.setIcon(ic)

app = QApplication(sys.argv)
widget = QWidget()
layout = QHBoxLayout()
widget.setLayout(layout)

checked = True
button = QPushButton()
button.setFlat(True)
button.clicked.connect(abu)
button.setStyleSheet('border:none')
layout.addWidget(button)

icon1 = QIcon("off_button.png")
icon2 = QIcon("on_button.png")
button.setIcon(icon1)
button.setIconSize(QtCore.QSize(30, 30))

widget.show()
app.exec_()