tkinter optionmenu first option vanishes

Question

A ttk optionmenu widget starts out with all of its values in the dropdown. Upon selecting any value, the first value in the list vanishes, never to reappear...

Does

Answer 1

It seems that with ttk.OptionMenu the first entry in the options list must be left blank:

import tkinter.ttk as ttk
import tkinter as tk

a = tk.Tk()

options = ['', '1', '2', '3']
value = tk.StringVar()
value.set(options[1])

masterframe = ttk.Frame()
masterframe.pack()

dropdown = ttk.OptionMenu(masterframe, value, *options)
dropdown.pack()

a.mainloop()

Source: http://www.pyinmyeye.com/2012/08/tkinter-menubutton-demo.html