如何在Tkinter中滚动一组标签小部件？

import tkinter as tk

def on_mousewheel(event):
    canvas.yview_scroll(int(-1*(event.delta/120)), "units")

root = tk.Tk()
root.geometry("400x300")

# 创建一个Canvas和Scrollbar
canvas = tk.Canvas(root)
canvas.pack(side=tk.LEFT, fill=tk.BOTH, expand=True)

scrollbar = tk.Scrollbar(root, command=canvas.yview)
scrollbar.pack(side=tk.RIGHT, fill=tk.Y)

canvas.configure(yscrollcommand=scrollbar.set)
canvas.bind_all("<MouseWheel>", on_mousewheel)

# 创建一个Frame作为滚动区域
scrollable_frame = tk.Frame(canvas)
canvas.create_window((0, 0), window=scrollable_frame, anchor="nw")

# 添加标签小部件到滚动区域
for i in range(20):
    label = tk.Label(scrollable_frame, text=f"Label {i+1}")
    label.pack()

# 更新Canvas的滚动区域大小
scrollable_frame.update_idletasks()
canvas.configure(scrollregion=canvas.bbox("all"))

root.mainloop()