import sys
from PyQt4 import QtGui, QtCore


class Example(QtGui.QWidget):

    def __init__(self):
        super(Example, self).__init__()

        self.initUI()

    def initUI(self):

        btn = QtGui.QPushButton(self)

        vbox = QtGui.QVBoxLayout()
        vbox.addWidget(btn)

        self.setLayout(vbox)

        QtCore.QObject.connect(btn, QtCore.SIGNAL("clicked()"), self.revealButton)

        self.setGeometry(300, 300, 250, 150)
        self.setWindowTitle('Signal & slot')
        self.show()

    def revealButton(self):
        print("kuku")

def main():

    app = QtGui.QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())


if __name__ == '__main__':
    main()