Python3.x tkinter treeview 如何在获取所选项目时将设置的对象作为对象返回

我正在为TreeView的每一行插入一个id和名称以及实际的类项目. 当我 Select 一行并希望取回该对象时，我得到的是一个字符串对象，而不是类对象.如何取回类对象而不是字符串？

import tkinter as tk
from tkinter import ttk

class TreeViewApp(tk.Tk):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.geometry("600x400+400+50")
        self.columnconfigure(0, weight=1)
        self.rowconfigure(0, weight=1)

        frame = ttk.Frame(self)
        frame.columnconfigure(0, weight=1)
        frame.rowconfigure(0, weight=1)
        frame.grid(column=0, row=0, sticky="nesw")

        tablesDG = ttk.Treeview(frame, height=5)
        tablesDG.bind("<<TreeviewSelect>>", self.onListSelect)
        tablesDG['columns'] = ('id', 'name', 'data')
        tablesDG.heading('#0', text="")
        tablesDG.heading('id', text="")
        tablesDG.heading('name', anchor='w', text=" Name")
        tablesDG.heading('data', text="")
        tablesDG.column('#0', width= 0, stretch=False)
        tablesDG.column('id', width=0, stretch=False)
        tablesDG.column('name', anchor='w', width=100)
        tablesDG.column('data', width= 0, stretch=False)
        tablesDG.grid(column=0, row=0, sticky="nesw")
        # creating row objects.  
        # Note that the data column I am saving the actual object for retrieval later
        for x in range(5):
            obj = dataDTO()
            obj.id = x
            obj.name = f'obj{x}'
            tablesDG.insert('', 'end', values=(obj.id, obj.name, obj))

# output of print.  Notice that the class of data is string and not dataDTO class object.
# {'text': '', 'image': '', 'values': [0, 'obj0', '<__main__.dataDTO object at 0x000002BA40075C90>'], 'open': 0, 'tags': ''}
# <class 'str'>

    def onListSelect(self, event):
        selected_iid = event.widget.selection()[0]
        row = event.widget.item(selected_iid)
        print(row)
        print(type(row['values'][2]))

class dataDTO():
    pass

TreeViewApp()
tk.mainloop()

如您所见，onListSelect方法将类型作为字符串返回，而不是作为插入的对象.如何让它返回插入的对象？