synchronize two scrollbars

sync_scrollbar

# -*- coding: utf-8 -*-
import sys
from PySide import QtCore, QtGui

class Ui_Window_scroll(object):
    def setupUi(self, Window_scroll):
        Window_scroll.setObjectName("Window_scroll")
        self.centralwidget = QtGui.QWidget(Window_scroll)
        self.centralwidget.setObjectName("centralwidget")
        self.gridLayout = QtGui.QGridLayout(self.centralwidget)
        self.gridLayout.setObjectName("gridLayout")
        self.listWidget_src = QtGui.QListWidget(self.centralwidget)
        self.gridLayout.addWidget(self.listWidget_src, 0, 0, 1, 1)
        self.listWidget_dst = QtGui.QListWidget(self.centralwidget)
        self.gridLayout.addWidget(self.listWidget_dst, 0, 1, 1, 1)
        Window_scroll.setCentralWidget(self.centralwidget)
        QtCore.QMetaObject.connectSlotsByName(Window_scroll)


if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    MainWindow = QtGui.QMainWindow()
    ui = Ui_Window_scroll()
    ui.setupUi(MainWindow)
    
    ui.listWidget_src.verticalScrollBar().valueChanged.connect(\
                                          ui.listWidget_dst.verticalScrollBar().setValue)
    ui.listWidget_dst.verticalScrollBar().valueChanged.connect(\
                                          ui.listWidget_src.verticalScrollBar().setValue)
    
    for i in range(100):
        ui.listWidget_src.addItem(QtGui.QListWidgetItem("Item {}".format(i)))
        ui.listWidget_dst.addItem(QtGui.QListWidgetItem("Item {}".format(i)))
    MainWindow.show()
    MainWindow.setAttribute(QtCore.Qt.WA_DeleteOnClose)
    sys.exit(app.exec_())