如何使用pack创建左、右、中框架？

import tkinter as tk

root = tk.Tk()
root.geometry("600x400")

left_frame = tk.Frame(root, bg="red")
left_frame.pack(side="left", expand=True, fill="both")

right_frame = tk.Frame(root, bg="green")
right_frame.pack(side="right", expand=True, fill="both")

center_frame = tk.Frame(root, bg="blue")
center_frame.pack(side="top", expand=True, fill="both")

label_left = tk.Label(left_frame, text="Left Frame", bg="red")
label_left.pack(pady=10)

label_right = tk.Label(right_frame, text="Right Frame", bg="green")
label_right.pack(pady=10)

label_center = tk.Label(center_frame, text="Center Frame", bg="blue")
label_center.pack(pady=10)

root.mainloop()