我有一個(gè)有多行的表單。按 Enter 鍵會(huì)打開一個(gè)選項(xiàng)窗口。但每次我按回車鍵時(shí)，它都會(huì)打開一個(gè)新的選項(xiàng)窗口。我如何控制和檢查選項(xiàng)窗口是否打開然后不打開選項(xiàng)窗口。import tkinter as tkfrom tkinter import ttkfrom tkinter import *from tkinter import messagebox# Directory/File processing librariesimport osimport configparserimport csvdef callback():    #messagebox.showinfo("Netezza", Folder_Name_var.get())    #messagebox.showinfo("Netezza", Table_Name_var.get() )    config = configparser.ConfigParser()    config.read('C:\\aa\\config.ini')    #for value in config['Folder']: print(value)    for key in config.items('Folder'):        print (key[1].replace('{Folder_Name}',Folder_Name_var.get()))        os.makedirs(key[1].replace('{Folder_Name}',Folder_Name_var.get()),exist_ok=True)def click_tv(event):    #messagebox.showinfo("Inside")    selected=trv.focus()    print(trv.item(selected))def press_enter(event):    #messagebox.showinfo("Inside")    selected=trv.focus()    print(trv.item(selected))    print(str((event.keysym)))    if str((event.keysym))=='Return':        option_wnd=Toplevel(root)        option_wnd.geometry('200x200')        option_wnd.title('Option Window')        option_wnd.grab_set()        #option_wnd.pack()def selection_change(event):    selected = trv.selection()[0]    print('You clicked on', trv.item(selected))    #option_wnd.mainloop()root = Tk()Folder_Name_var = tk.StringVar()Table_Name_var = tk.StringVar()# This is the section of code which creates the main windowroot.geometry('873x498')root.configure(background='#63B8FF')root.title('Automation Software - Blue Shield of California')pic= Canvas(root, height=100, width=100)#pic= Canvas(root, height=225, width=580)#picture_file = PhotoImage(file = 'c:\\aa\\bsc.png')#pic.create_image(0, 0, anchor=NW, image=picture_file)#pic.place(x=5, y=5)每次我在根窗口上按 Enter 鍵時(shí)，都會(huì)打開一個(gè)彈出窗口。我需要控制它。如果彈出窗口打開，那么我們不應(yīng)該允許另一個(gè)彈出窗口打開。