Quitting Tkinter drop down menu

The problem with calling root.quit() in function() was caused by the fact that it's a variable local to the edit_or_retrieve() function. This can be fixed by passing it as an argument to function(), but unfortunately, the OptionMenu widget is the thing that does this, and you can't modify it.

However you can workaround this and pass extra arguments to the function by creating a short lambda function that acts as a software "shim" and passes the extra argument to function() when it's called.

Below is your code with the modifications to do this:

from tkinter import *def edit_or_retrieve():    root = Tk()    root.title("Main Menu")    menu = Frame(root)    menu.pack(pady=5, padx=50)    var = StringVar(root)    options = ['Enter',               'Edit',               'Retrieve',               'Report 1 - Dates of birth',               'Report 2 - Home phone numbers',               'Report 3 - Home addresses',               'Log off',]    option = OptionMenu(menu, var, *options,                        # use lambda to pass local var as extra argument                        command=lambda x: function(x, root))    var.set('Select')    option.grid(row=1, column=1)    root.mainloop()def function(value, root):  # note added "root" argument    if value == 'Edit':        edit()    if value == 'Enter':        enter()    if value == 'Retrieve':        display()    if value == 'Report 1 - Dates of birth':         reportone()    if value == 'Report 2 - Home phone numbers':         reporttwo()    if value == 'Report 3 - Home addresses':         reportthree()    if value == 'Log off':        root.quit()edit_or_retrieve()