return multiple values from list box tkinter python

I'm trying to return the selection value/s from a list box.

first, I have a combo box in which the user needs to select the area ( A, B, C....)
After the area is being selected, a list box appeared on the widget and the user needs to select other options. When I try to select values from the list box it prints nothing, empty list.

How do I return the other options?

• this is a part of the code

   def sheetChosenLabel(event):
  
      area = combo_sheet.get()  # Get the selection from the user
      area_listbox = Listbox(frame3, background=PowderBlue, font=("ariel", 9), relief="sunken")
      area_listbox.place(relx=0.09, rely=0.4, height=100, width=100)
      area_listbox.configure(selectmode=MULTIPLE)
  
      for item in Sheets[area]:
          area_listbox.insert(END, item)
  
      results = []
      for index in area_listbox.curselection():
          results.append(area_listbox.get(index))
      print results
  

GUI

Since you get the selected items just after area_listbox is created, you will get nothing as nothing is selected.

You can do it in a function triggered by a button instead. Also better create the listbox outside sheetChosenLabel() and update its content inside the function.

Below is an example based on your posted code:

import tkinter as tk
from tkinter import ttk

# sample data
Sheets = {
    'A': (f'A{i}' for i in range(1, 10)),
    'B': (f'B{i}' for i in range(1, 20)),
    'C': (f'C{i}' for i in range(1, 8)),
}


def sheetChosenLabel(event):
    # update listbox based on selected area
    area = combo_sheet.get()
    area_listbox.delete(0, tk.END)
    for item in Sheets[area]:
        area_listbox.insert(tk.END, item)


def check_result():
    # get and show the selected items in listbox
    result = [area_listbox.get(i) for i in area_listbox.curselection()]
    print(result)


root = tk.Tk()

frame3 = tk.Frame(root)
frame3.pack(fill=tk.BOTH, expand=1, padx=5, pady=5)

combo_sheet = ttk.Combobox(frame3, values=list(Sheets.keys()), state='readonly')
combo_sheet.pack(padx=10, pady=5)
combo_sheet.bind('<<ComboboxSelected>>', sheetChosenLabel)

area_listbox = tk.Listbox(frame3, bg='PowderBlue', font='Arial 9', relief='sunken', selectmode=tk.MULTIPLE)
area_listbox.pack(padx=10, pady=5)

check_button = tk.Button(frame3, text='Check', command=check_result)
check_button.pack(padx=10, pady=5)

root.mainloop()