I'm trying to print out the value selected in the option menu but only the first value gets printed everytime I run the code, even if I change my selection to b or c. Not sure where I'm wrong.This is my code:
from tkinter import *
window=Tk()
window.geometry("700x400")
options=StringVar(window)
options.set("a")
menu=OptionMenu(window,options, "a","b","c")
menu.grid(row=2,column=2)
selection=options.get()
print(selection)
Instead of tracing the variable, you can use the command option of the OptionMenu. Each time a menu item is clicked, the command is called. This command takes one argument: the item which is selected.
import tkinter as tk
def callback(selection):
print(selection)
root = tk.Tk()
options = tk.StringVar()
menu = tk.OptionMenu(root, options, 'a', 'b', 'c', command=callback)
menu.pack()
options.set('a')
root.mainloop()
In this case, the initially selected item is not printed because the user have not clicked on it. If you need options.set('a') to trigger your callback, then you will have to trace the variable like in mentalita's answer.
First of all, you need to invoke Tk's mainloop at the end of your code. Also, try tracing the options class variable.
From the docs: You can use the trace method to attach “observer” callbacks to the variable. The callback is called whenever the contents change.
import tkinter as tk
root = tk.Tk()
options = tk.StringVar()
options.trace_add('write', lambda *args: print(options.get()))
menu = tk.OptionMenu(root, options, 'a', 'b', 'c')
menu.pack()
options.set('a')
root.mainloop()
trace is deprecated and options.trace_add('write', lambda *args: print(options.get())) should be used instead.You're assigning selection before the user has the chance to change the selected option.
Putting it in a function that calls when a 'save' button is pressed would likely be the simplest fix. You could also use a recursion loop to update it in real time but it's not a clean solution.
I'm assuming you've already included root.mainloop() in your actual script.
try this
import tkinter
window=tkinter.Tk()
window.geometry("700x400")
option_Menu = tkinter.StringVar(window)
options = ("a","b","c")
menu = tkinter.OptionMenu(window,option_Menu,*options)
menu.grid(row=2,column=2)
option_Menu.set(2)
selection=option_Menu.get()
print(selection)
tkinter.mainloop()
