PYTHON

change default option optionmenu tkinter

"""
Change selected option optionmenu tkinter.
If at any time you change the value of the variable, it will update your widget.
"""

import tkinter as tk # First we import tkinter as tk

root = tk.Tk() # We then create the root
optionList = ('a', 'b', 'c') # And a list for the selections
v = tk.StringVar() # Then create a stringvar
v.set(optionList[0])  # Here is the initially selected value (we set the stringvar to optionlist[0], aka choose the "a")
om = tk.OptionMenu(root, v, *optionList) # Create the optionmenu
om.pack() # Pack it

v.set(optionList[2]) # This one will be the final selected value("c"), you can change the number to 1 or 0 to fit your needs.
root.mainloop() # And mainloop

"""
FYI, the numbering starts from 0, so to select "a" you need to change the varaible to "0"
"""