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pythontkinterconfigurationoptionmenu

How to modify global variable via function based on Optionmenu selection


I am pretty new to python and am trying to create a product configurator using tkinter optionmenu. I need to use multiple optionmenus and each value selected should create the next set of data for the next optionmenu. I have researched everything I can think to get it right, to no avail.

NOTE: the second optionmenu is in a note, as it is not working with the current configuration. Also, will need 4 optionmenus in total, all based on values selected before them.

Edited code:

from tkinter import *


def openForm():
    print('Open Form')
    return


def openParts():
    print('Open Parts')
    return


capChoice = ['No Lift Selected']


def capFilter(liftSelection):
    global capChoice
    if liftSelection == 'Arm':
        capChoice = ['50kg', '100kg', '200kg', '300kg']
    elif liftSelection == 'Arm (Food Grade)':
        capChoice = ['75kg']
    elif liftSelection == 'Rail':
        capChoice = ['125kg', '300kg']
    elif liftSelection == 'Drive':
        capChoice = ['125kg', '300kg']
    print(capChoice)


lengthChoice = ['No Capacity Selected']


def lengthFilter(lengthSelection):
    global lengthChoice
    if lengthSelection == '50kg' and capChoice == 'Arm':
        lengthChoice = ['3m']
    elif lengthSelection == '75kg':
        lengthChoice = ['4.2m']
    elif lengthSelection == '100kg' and capChoice == 'Arm':
        lengthChoice = ['3m', '4m', '5m']
    elif lengthSelection == '125kg':
        lengthChoice = ['N/A']
    elif lengthSelection == '200kg' and capChoice == 'Arm':
        lengthChoice = ['3m', '4m', '5m']
    elif lengthSelection == '300kg' and capChoice == 'Arm':
        lengthChoice = ['3m', '4m']
    elif lengthSelection == '300kg' and capChoice == 'Rail':
        lengthChoice = ['N/A']
    elif lengthSelection == '300kg' and capFilter() == 'Drive':
        lengthChoice = ['N/A']


app = Tk()
app.title('QL Form')
app.geometry('560x460+200+200')

menubar = Menu(app)
filemenu = Menu(menubar, tearoff=0)
filemenu.add_command(label='Form', command=openForm)
filemenu.add_command(label='Req Parts', command=openParts)
filemenu.add_separator()
filemenu.add_command(label='Quit', command=app.quit)
menubar.add_cascade(label='Page', menu=filemenu)

app.config(menu=menubar)

liftType = StringVar()
liftType.set('Lift Type')
files = ['Arm', 'Arm (Food Grade)', 'Rail', 'Drive']
liftDropDown = OptionMenu(app, liftType, *files, command=capFilter)
liftDropDown.pack()

liftCap = StringVar()
liftCap.set('Capacity')
capDropDown = OptionMenu(app, liftCap, *capChoice, command=lengthFilter)
capDropDown.pack()

liftLength = StringVar()
liftLength.set('Length')
capDropDown = OptionMenu(app, liftLength, *lengthChoice, command=lengthFilter)
capDropDown.pack()


app.mainloop()

Code before:

from tkinter import *


def openForm():
    print('Open Form')
    return


def openParts():
    print('Open Parts')
    return


def capFilter(selection):
    global capChoice
    if selection == 'Arm':
        capChoice = ['50kg', '100kg', '200kg', '300kg']
    elif selection == 'Arm (Food Grade)':
        capChoice = ['75kg']
    elif selection == 'Rail':
        capChoice = ['125kg', '300kg']
    elif selection == 'Drive':
        capChoice = ['125kg', '300kg']
    print(capChoice)
    return capChoice



def lengthFilter(selection):
    if selection == '50kg' and capFilter() == 'Arm':
        lengthChoice = ['3m']
    elif selection == '75kg':
        lengthChoice = ['4.2m']
    elif selection == '100kg' and capFilter() == 'Arm':
        lengthChoice = ['3m', '4m', '5m']
    elif selection == '125kg':
        lengthChoice = ['N/A']
    elif selection == '200kg' and capFilter() == 'Arm':
        lengthChoice = ['3m', '4m', '5m']
    elif selection == '300kg' and capFilter() == 'Arm':
        lengthChoice = ['3m', '4m']
    elif selection == '300kg' and capFilter() == 'Rail':
        lengthChoice = ['N/A']
    elif selection == '300kg' and capFilter() == 'Drive':
        lengthChoice = ['N/A']
    return lengthChoice


app = Tk()
app.title('QL Form')
app.geometry('560x460+200+200')

menubar = Menu(app)
filemenu = Menu(menubar, tearoff=0)
filemenu.add_command(label='Form', command=openForm)
filemenu.add_command(label='Req Parts', command=openParts)
filemenu.add_separator()
filemenu.add_command(label='Quit', command=app.quit)
menubar.add_cascade(label='Page', menu=filemenu)

app.config(menu=menubar)

liftType = StringVar()
liftType.set('Lift Type')
files = ['Arm', 'Arm (Food Grade)', 'Rail', 'Drive']
liftDropDown = OptionMenu(app, liftType, *files, command=capFilter)
liftDropDown.pack()


'''
liftCap = StringVar()
liftCap.set('Capacity')
capDropDown = OptionMenu(app, liftCap, *capChoice, command=lengthFilter)
capDropDown.pack()
'''

app.mainloop()

Solution

  • cap_dropdown copies values from cap_choice at start but later it doesn't use it - so if you even change values in cap_choice it will not work.

    Inside cap_filter you have to replace items directly in cap_dropdown.

    import tkinter as tk
    
    def cap_filter(selection):
        options = {
            'Arm': ['50kg', '100kg', '200kg', '300kg'],
            'Arm (Food Grade)': ['75kg'],
            'Rail': ['125kg', '300kg'],
            'Drive': ['125kg', '300kg'],
        }
    
        if selection in options:
            items = options[selection]    
        else:
            items = []
        print(items)    
    
        # remove old elements
        cap_dropdown['menu'].delete(0, 'end')
    
        # add new items
        for text in items:
            cap_dropdown['menu'].add_command(label=text, command=lambda arg=text:length_filter(arg))
    
    
    def length_filter(selection):
        type_ = lift_type.get()
    
        if selection == '50kg' and type_ == 'Arm':
            length_choice = ['3m']
        elif selection == '75kg':
            length_choice = ['4.2m']
        elif selection == '100kg' and type_ == 'Arm':
            length_choice = ['3m', '4m', '5m']
        elif selection == '125kg':
            length_choice = ['N/A']
        elif selection == '200kg' and type_ == 'Arm':
            length_choice = ['3m', '4m', '5m']
        elif selection == '300kg' and type_ == 'Arm':
            length_choice = ['3m', '4m']
        elif selection == '300kg' and type_ == 'Rail':
            length_choice = ['N/A']
        elif selection == '300kg' and type_ == 'Drive':
            length_choice = ['N/A']
        else:
            length_choice = ['N/A']
    
        print(length_choice)
    
    app = tk.Tk()
    
    lift_type = tk.StringVar()
    lift_type.set('Lift Type')
    files = ['Arm', 'Arm (Food Grade)', 'Rail', 'Drive']
    
    lift_dropdown = tk.OptionMenu(app, lift_type, *files, command=cap_filter)
    lift_dropdown.pack()
    
    lift_cap = tk.StringVar()
    lift_cap.set('Capacity')
    cap_choice = ['']
    
    cap_dropdown = tk.OptionMenu(app, lift_cap, *cap_choice, command=length_filter)
    cap_dropdown.pack()
    
    app.mainloop()