PyQt5--QProgressBar

 # -*- coding:utf-8 -*-
 '''
 Created on Sep 20, 2018

 @author: SaShuangYiBing

 Comment:
 '''
 import sys
 from PyQt5.QtCore import QBasicTimer
 from PyQt5.QtWidgets import QApplication,QWidget,QProgressBar,QPushButton

 class New_test(QWidget):
     def __init__(self):
         super().__init__()
         self.initUI()

     def initUI(self):
         self.pbar = QProgressBar(self)
         self.pbar.setGeometry(30,40,200,25)

         self.btn = QPushButton('Start',self)
         self.btn.move(75,80)
         self.btn.clicked.connect(self.doAction)

         self.timer = QBasicTimer()
         self.step = 0

         self.setGeometry(300,300,280,170)
         self.setWindowTitle('QProgress Bar')
         self.show()

     def timerEvent(self, e):
         if self.step >= 100:
             self.timer.stop()
             self.btn.setText('Finished')
             return
         self.step += 1
         self.pbar.setValue(self.step)

     def doAction(self,e):
         if self.timer.isActive():
             self.timer.stop()
             self.btn.setText('Start')
         else:
             self.timer.start(100,self)
             self.btn.setText('Stop')

 if __name__ == '__main__':
     app = QApplication(sys.argv)
     ex = New_test()
     sys.exit(app.exec_())