如何在python PYQt4中保存几个QtextEdits的文本？

当我是python PyQt初学者时，能否请您帮助我解决问题...我已经使用python PyQt4创建了一个简单的应用程序，用于简单的数学计算，并在textEdit2和textEdit3中生成了结果，当我单击“计算”时，一切都很好按钮，值出现在上面的textedits中...我想要的是将结果保存在相同的文本编辑中，以便下次我打开应用程序并打开数据文件时，我发现所有内容都在适当的位置。我创建了save和open操作...但是将所有结果保存在同一文本编辑中。

我将附加我的代码以及需要保存结果的主窗口以及保存并打开应用程序并将所有结果合并为一个文本后的另一张照片

enter code here
import sys  
from PyQt4 import QtCore, QtGui, uic   
import os   #os used to interface with windows  
import datetime as dt
import pickle
qtCreatorFile = "save.ui" # Enter ui file here

Ui_MainWindow, QtBaseClass = uic.loadUiType(qtCreatorFile)   

class MyApp(QtGui.QMainWindow, Ui_MainWindow):  
    def __init__(self):                         

        super (MyApp,self).__init__()       
        Ui_MainWindow.__init__(self)
        self.setupUi(self)
        self.initUI()
        self.calc.clicked.connect(self.Bss)

    def Bss (self):
        x = float(self.textEdit.toPlainText())     
        y = float(self.textEdit1.toPlainText())
        z= x+y
        w= x**2

        z_string = str(z)         #convert z value to a string then add this  string to textEdit and set as Text
        self.textEdit2.setText(z_string)
        w_string = str(w)
        self.textEdit3.setText(w_string)

    def initUI(self):           #QAction class insert New,action save in the main menue bar
        newAction = QtGui.QAction('New', self)  
        newAction.setShortcut('Ctrl+N')
        newAction.setStatusTip('Create new file')
        newAction.triggered.connect(self.newFile)  
        saveAction = QtGui.QAction('Save as', self)
        saveAction.setShortcut('Ctrl+S')
        saveAction.setStatusTip('Save current file')
        saveAction.triggered.connect(self.saveFile)
        openAction = QtGui.QAction('Open', self)
        openAction.setShortcut('Ctrl+O')
        openAction.setStatusTip('Open a file')
        openAction.triggered.connect(self.openFile)
        closeAction = QtGui.QAction('Close', self)
        closeAction.setShortcut('Ctrl+Q')
        closeAction.setStatusTip('Close Notepad')
        closeAction.triggered.connect(self.close)
        menubar = self.menuBar()
        fileMenu = menubar.addMenu('&File')
        fileMenu.addAction(newAction)
        fileMenu.addAction(saveAction)
        fileMenu.addAction(openAction)
        fileMenu.addAction(closeAction)
        self.show()
        self.statusBar()

    def newFile(self): #create a new function and remove all values in the QTEXTedit
        self.textEdit.clear()
        self.textEdit1.clear()
        self.textEdit2.clear()
        self.textEdit3.clear()                

    def openFile(self):
        self.text = QtGui.QTextEdit(self)
        filename = QtGui.QFileDialog.getOpenFileName(self, 'Open File', os.getenv('HOME'))
        f = open(filename, 'r')
        filedata = f.read()
        self.textEdit1.setText(filedata)
        self.textEdit2.setText(filedata)
        self.textEdit3.setText(filedata)
        f.close()
        self.show()

    def saveFile(self):   # saving argument values in a filedata
        self.text = QtGui.QTextEdit(self)
        filename = QtGui.QFileDialog.getSaveFileName(self, 'Save File', os.getenv('HOME'))
        f = open(filename, 'w')
        filedata = self.textEdit1.toPlainText()
        f.write(filedata)
        filedata = self.textEdit2.toPlainText()
        f.write(filedata)
        filedata = self.textEdit3.toPlainText()
        f.write(filedata)
        f.close()

    def closeEvent(self, event):
        reply = QtGui.QMessageBox.question(self, 'Message',
        "Are you sure to quit?", QtGui.QMessageBox.Yes | 
        QtGui.QMessageBox.No, QtGui.QMessageBox.No)

        if reply == QtGui.QMessageBox.Yes:
            event.accept()
        else:
            event.ignore()
if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    window = MyApp()
    window.show()
    sys.exit(app.exec_())