Python 3如何暂时禁用跟踪变量

Q1：如何暂时禁用跟踪变量
我有一个跟踪的变量字段,我想暂时禁用跟踪,以便我可以更改字段的值而不触发对跟踪功能的调用.

是否有意义？

可能是我做错了(我加入了一段代码)：

我有一个下拉列表,显示了我可以选择的项目列表.
我有第二个下拉列表,为第一个下拉菜单中的每个项目显示“子项目”列表,当我更改第一个下拉菜单时,当然必须更新这些项目.

Q2：问题是,当第一个下拉菜单发生变化时,如何“重新包装”第二个下拉菜单？

这是代码：

import tkinter as tk

WORKINGWINDOWWIDTH  = 800                         # Width for the working window
WORKINGWINDOWHEIGHT = 800                         # Height for the working window

root = tk.Tk()

w = tk.Canvas(root,width=WORKINGWINDOWWIDTH - 10,height=WORKINGWINDOWHEIGHT - 10,bg="darkred")

def display_parameters(*args):
    print("args: {0},and I have the following option: {1}".format(args,functionChoiceVar.get()))
    if functionChoiceVar.get() == "Option 1":
        print("I picked the first one...")
        print("How do I repack the presets?")
    elif functionChoiceVar.get() == "Option 2":
        print("I picked the second one...")
    return

def display_options(*args):
    print("args: {0},and I have the following suboption: {1}".format(args,presetChoiceVar.get()))
    return

functionChoiceVar = tk.StringVar(root)
functionChoices   = ['Option 1','Option 2']
functionOption    = tk.OptionMenu(root,functionChoiceVar,*functionChoices)
functionOption.pack(side='left',padx=10,pady=10)
functionOption.place(x= 10,y=10)
functionChoiceVar.set('Option 1')
functionChoiceVar.trace("w",display_parameters)

presetChoiceVar   = tk.StringVar(root)
presetChoices11   = ['Suboption 11','Suboption 12','Suboption 13','Suboption 14','Suboption 15']
presetChoices12   = ['Suboption 21','Suboption 22','Suboption 23','Suboption 24','Suboption 25']
presetOption      = tk.OptionMenu(root,presetChoiceVar,*presetChoices11)
presetOption.pack(side='left',pady=10)
presetOption.place(x= 100,y=10)
presetChoiceVar.set('Suboption 11')
presetChoiceVar.trace("w",display_options)