CODEWITHSUNDEEP
python-3.xtkinter
Dana Yeger
Dana Yeger

Reputation: 711

python: option menu via TKinter not showing in my UI

So i have simple application with 2 labels and 2 option_menu:

import sys

if sys.version_info[0] >= 3:
    import tkinter as tk
else:
    import Tkinter as tk


class App(tk.Frame):

    def __init__(self, master):
        tk.Frame.__init__(self, master)


    def update_options(self, *args):
        countries = self.dict[self.variable_a.get()]
        self.variable_b.set(countries[0])

        menu = self.optionmenu_b['menu']
        menu.delete(0, 'end')

        for country in countries:
            menu.add_command(label=country, command=lambda nation=country: self.variable_b.set(nation))


    def create_labels(self):
        tk.Label(root, text='').grid(row=0)
        tk.Label(root, text='Produtct:').grid(row=1, padx=10, pady=5)
        tk.Label(root, text='Application:').grid(row=2, padx=10, pady=5)

    def create_option_menu(self):
        self.dict = {
            'Mobile': ['ios', 'android'],
            'Test': ['1', '2', '3']
        }

        self.variable_a = tk.StringVar(self)
        self.variable_b = tk.StringVar(self)

        self.variable_a.trace('w', self.update_options)

        self.optionmenu_a = tk.OptionMenu(self, self.variable_a, *self.dict.keys()).grid(row=1, column=1, sticky="NSWE")
        self.optionmenu_b = tk.OptionMenu(self, self.variable_b, '').grid(row=1, column=1, sticky="NSWE")

        self.variable_a.set('Mobile')


if __name__ == "__main__":
    root = tk.Tk()
    app = App(root)
    app.create_labels()
    app.create_option_menu()
    app.mainloop()

And when I select some option from the first option menu the second option menu changed accordingly.

And i have problem that I cannot see my option menu and i cannot figure why. This is my exception:

Exception in Tkinter callback Traceback (most recent call last):
File "C:\Python37\lib\tkinter_init_.py", line 1705, in call return self.func(*args) File "C:/HW_Automation_Python/robot-framework/gui/init.py", line 19, in update_options menu = self.optionmenu_b['menu'] TypeError: 'NoneType' object is not subscriptable

Upvotes: 0

Views: 196

Answers (1)

Delrius Euphoria
Delrius Euphoria

Reputation: 15098

Just change your respective part of code to this:

self.optionmenu_a = tk.OptionMenu(root, self.variable_a, *self.dict.keys())
self.optionmenu_a.grid(row=1, column=1, sticky="NSWE")
self.optionmenu_b = tk.OptionMenu(root, self.variable_b, '')
self.optionmenu_b.grid(row=2, column=1, sticky="NSWE")

  • Firstly, you are saying grid() on the same line as declaration which makes the variable have None as the value. Check here for more information on this.

  • Secondly, you forgot to specify a master option, like root for the widget.

Upvotes: 1

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