# -*- coding: utf-8 -*- 
from PyQt4.QtCore import * 
from PyQt4.QtGui import * 
import sys 
import os 
import time

class Test(QDialog): 
    def __init__(self,parent=None): 
        super(Test,self).__init__(parent) 
        self.listFile=QListWidget() 
        self.btnStart=QPushButton('Start') 
        layout=QGridLayout(self) 
        layout.addWidget(self.listFile,0,0,1,2) 
        layout.addWidget(self.btnStart,1,1) 
        self.connect(self.btnStart,SIGNAL('clicked()'),self.slotAdd) 
    def slotAdd(self): 
        for n in range(10): 
            str_n='File index {0}'.format(n) 
            self.listFile.addItem(str_n) 
            QApplication.processEvents() 
            time.sleep(1) 
app=QApplication(sys.argv) 
dlg=Test() 
dlg.show() 
sys.exit(app.exec_())