from PyQt4.QtGui import *
from PyQt4.QtCore import *

import sys

class myListWidget(QListWidget):

   def Clicked(self,item):
      QMessageBox.information(self, "ListWidget", "You clicked: "+item.text())

def main():
   app = QApplication(sys.argv)
   listWidget = myListWidget()

   #Resize width and height
   listWidget.resize(300,120)

   listWidget.addItem("Item 1"); 
   listWidget.addItem("Item 2");
   listWidget.addItem("Item 3");
   listWidget.addItem("Item 4");

   listWidget.setWindowTitle('PyQT QListwidget Demo')
   listWidget.itemClicked.connect(listWidget.Clicked)

   listWidget.show()
   sys.exit(app.exec_())

if __name__ == '__main__':
   main()