在tkinter中添加notebook标签-如何使用基于类的结构？(Python 2)

import tkinter as tk
from tkinter import ttk

class MyApplication(tk.Tk):
    def __init__(self):
        super().__init__()
        self.title("My Application")
        
        self.notebook = ttk.Notebook(self)
        self.notebook.pack(fill=tk.BOTH, expand=True)
        
        self.tab1 = ttk.Frame(self.notebook)
        self.notebook.add(self.tab1, text="Tab 1")
        
        self.tab2 = ttk.Frame(self.notebook)
        self.notebook.add(self.tab2, text="Tab 2")
        
        self.tab3 = ttk.Frame(self.notebook)
        self.notebook.add(self.tab3, text="Tab 3")
        
        self.mainloop()

if __name__ == "__main__":
    app = MyApplication()