import sys
from PyQt4 import QtCore, QtGui

def myfunc(mystr):
    return mystr*2

class MyWidget(QtGui.QWidget):
    def on_go_clicked(self):
        self.textLinks.setText(myfunc(self.searchLine.text()))

    def __init__(self, parent=None):
        QtGui.QWidget.__init__(self, parent)

        self.go = QtGui.QPushButton("Run")
        self.go.setFont(QtGui.QFont("Times", 18, QtGui.QFont.Bold))

        self.searchLine = QtGui.QLineEdit()
        self.searchLine.setFont(QtGui.QFont("Times", 18, QtGui.QFont.Bold))

        self.textLinks = QtGui.QLabel()

        QtCore.QObject.connect(self.go,
                              QtCore.SIGNAL("clicked()"),
                              self.on_go_clicked)

        layout = QtGui.QVBoxLayout()
        layout.addWidget(self.go);
        layout.addWidget(self.searchLine);
        layout.addWidget(self.textLinks);
        self.setLayout(layout);


app = QtGui.QApplication(sys.argv)
widget = MyWidget()
widget.show()
sys.exit(app.exec_())