PyQt5--QComboBox

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

 @author: SaShuangYiBing

 Comment:
 '''
 import sys
 from PyQt5.QtWidgets import QApplication,QWidget,QComboBox,QLabel

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

     def initUI(self):
         self.lbl = QLabel('fruit',self)
         combo = QComboBox(self)
         combo.addItem('apple')
         combo.addItem('pair')
         combo.addItem('banana')
         combo.move(50,50)
         self.lbl.move(50,150)
         combo.activated[str].connect(self.onActive)

         self.setGeometry(300,300,300,200)
         self.setWindowTitle('QCombobox')
         self.show()

     def onActive(self,text):
         try:
             self.lbl.setText(text)
             self.lbl.adjustSize()
         except Exception as e:
             print (e)

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