我正在使用tkinter创建一个文本编辑器，但是当文件被保存时，标签消失了。 这是保存文件，打开文件和标记功能的代码。我读到为了保留标记，我应该使用dump（），但是我不知道将其放置在何处或如何工作。它应该在这三个功能之一中吗？以及如何将其连接到他们的内容？：

def open_file(self):
    open_return=filedialog.askopenfile(initialdir="/",title='Select File to open',filetypes= (("text files","*.txt"),("all files","*.*")))

    if (open_return !=None):
        self.text_area.delete(1.0,END)
        for line in open_return:
            self.text_area.insert(END,line)
        self.__file=open_return.name
        open_return.close()
def save_file(self):
    if self.__file== None:
        # Save as new file
        self.__file = filedialog.asksaveasfilename(initialfile='Untitled.txt',defaultextension=".txt",filetypes=[("All Files","*.*"),("Text Documents","*.txt")])

        if self.__file == "":
            self.__file = None
        else:


            file = open(self.__file,"w")
            file.write(self.text_area.get(1.0,END))
            file.close()


            self.master.title(os.path.basename(self.__file) + " - Notes")


    else:
        file = open(self.__file,"w")
        file.write(self.__thisTextArea.get(1.0,END))
        file.close()
def OnGreen(self):
    #With this function I highlight the selected text
    current_tags = self.text_area.tag_names("sel.first")
    if "p" in current_tags:
        self.text_area.tag_remove("p","sel.first","sel.last")
    else:
        self.text_area.tag_add("p","sel.last")
        self.text_area.tag_config("p",background="green",foreground="white")