Question

I am creating a Menu test for my restaurant as a project and I have the GUI set up how I want but I have run into a problem with the Button updating the value its sending. My plan is for a menu item to appear on the GUI when the button is pressed, the employees then check the appropriate checkboxes (ingredients), then click the sumbit and continue button and the next menu item appears and they continue on the test. Right now I have it set up to where the area for the menu items starts out blank, when I click the button the first time the first item in my list appears but then is never updated no matter how many times the button is pressed. I’m pretty sure I am just setting the counter (what my button is sending) up wrong but I am kinda stumped… Here is a picture of my GUI to hopefully show you what I mean as well as the code I have so far. Thanks for you help it is much appreciated!

from tkinter import *

class Example(Frame):

    def __init__(self, parent):
        Frame.__init__(self, parent, background="white")   

        self.parent = parent

        self.initUI()

    def initUI(self):

        self.parent.title("Wahoos Menu Test")
def main():

    def callBack(number):
        count = number + 1
        item(count)
    def item(number):
        menu = ['nft', 'nckt', 'cat', 'nck outer reef burrito',]
        m = Label(root, text=menu[number], fg="orange").grid(row=7, column=0)
    root = Tk()
    app = Example(root)
    #root.geometry("750x750+400+50")
    for r in range(20):
        for c in range(14):
            Label(root, text='',
                borderwidth=0).grid(row=r,column=c)
    count = -1
    B = Button(root, text ="Submit and Continue", relief=RIDGE, fg="black", command= lambda:callBack(count)).grid(row=19, column=7)
    L = Label(root, text="What comes in the following", fg="blue").grid(row=6, column=0)
    #I = Label(root, text="***Loop Items Here***", fg="blue").grid(row=7, column=0)
    V = Label(root, text="Veggies", fg="green").grid(row=1, column=11, sticky=W)
    v1 = IntVar()
    Checkbutton(root, text="Lettuce", variable=v1, fg="black").grid(row=2, column=11, sticky=W)
    v2 = IntVar()
    Checkbutton(root, text="Cabbage", variable=v2).grid(row=3, column=11, sticky=W)
    v3 = IntVar()
    Checkbutton(root, text="Cheese", variable=v3).grid(row=4, column=11, sticky=W)
    v4 = IntVar()
    Checkbutton(root, text="Ahee Rice", variable=v4).grid(row=5, column=11, sticky=W)
    v5 = IntVar()
    Checkbutton(root, text="Brown Rice", variable=v5).grid(row=6, column=11, sticky=W)
    v6 = IntVar()
    Checkbutton(root, text="Banzai Veg", variable=v6).grid(row=7, column=11, sticky=W)
    v7 = IntVar()
    Checkbutton(root, text="Red Cabbage", variable=v7).grid(row=8, column=11, sticky=W)
    v8 = IntVar()
    Checkbutton(root, text="Black Beans", variable=v8).grid(row=9, column=11, sticky=W)
    v9 = IntVar()
    Checkbutton(root, text="Cajun White Beans", variable=v9).grid(row=10, column=11, sticky=W)
    T = Label(root, text="Tortillas     ", fg="green").grid(row=1, column=12, sticky=W)
    t1 = IntVar()
    Checkbutton(root, text="Corn          ", variable=t1).grid(row=2, column=12, sticky=W)
    t2 = IntVar()
    Checkbutton(root, text="Flour", variable=t2).grid(row=3, column=12, sticky=W)
    P = Label(root, text="Proteins", fg="green").grid(row=1, column=13, sticky=W)
    p1 = IntVar()
    Checkbutton(root, text="Carne Asada", variable=p1).grid(row=2, column=13, sticky=W)
    p2 = IntVar()
    Checkbutton(root, text="Flamebroiled Chicken", variable=p2).grid(row=3, column=13, sticky=W)
    p3 = IntVar()
    Checkbutton(root, text="Blackened Chicken", variable=p3).grid(row=4, column=13, sticky=W)
    p4 = IntVar()
    Checkbutton(root, text="Flamebroiled Fish", variable=p4).grid(row=5, column=13, sticky=W)
    p5 = IntVar()
    Checkbutton(root, text="Pork", variable=p5).grid(row=6, column=13, sticky=W)
    p6 = IntVar()
    Checkbutton(root, text="Shrimp", variable=p6).grid(row=7, column=13, sticky=W)
    p7 = IntVar()
    Checkbutton(root, text="Tofu", variable=p7).grid(row=8, column=13, sticky=W)
    p8 = IntVar()
    Checkbutton(root, text="Blackened Mushroom", variable=p8).grid(row=9, column=13, sticky=W)
    p9 = IntVar()
    Checkbutton(root, text="Rice and Beans", variable=p9).grid(row=10, column=13, sticky=W)
    p10 = IntVar()
    Checkbutton(root, text="Banzai Veg", variable=p10).grid(row=11, column=13, sticky=W)
    S = Label(root, text="Sauces", fg="green").grid(row=1, column=14, sticky=W)
    s1 = IntVar()
    Checkbutton(root, text="Salsa", variable=s1).grid(row=2, column=14, sticky=W)
    s2 = IntVar()
    Checkbutton(root, text="Guacamole", variable=s2).grid(row=3, column=14, sticky=W)
    s3 = IntVar()
    Checkbutton(root, text="Sour Cream", variable=s3).grid(row=4, column=14, sticky=W)
    s4 = IntVar()
    Checkbutton(root, text="Roasted Pepper", variable=s4).grid(row=5, column=14, sticky=W)
    s5 = IntVar()
    Checkbutton(root, text="Ketchup", variable=s5).grid(row=6, column=14, sticky=W)
    s6 = IntVar()
    Checkbutton(root, text="Ranch", variable=s6).grid(row=7, column=14, sticky=W)
    s7 = IntVar()
    Checkbutton(root, text="Balsamic", variable=s7).grid(row=8, column=14, sticky=W)
    s8 = IntVar()
    Checkbutton(root, text="Mr. Lees", variable=s8).grid(row=9, column=14, sticky=W)
    s9 = IntVar()
    Checkbutton(root, text="Teriyaki", variable=s9).grid(row=10, column=14, sticky=W)
    s10 = IntVar()
    Checkbutton(root, text="Tapatio", variable=s10).grid(row=11, column=14, sticky=W)
    s11 = IntVar()
    Checkbutton(root, text="Cream Cheese", variable=s11).grid(row=12, column=14, sticky=W)
    s12 = IntVar()
    Checkbutton(root, text="Aoli", variable=s12).grid(row=13, column=14, sticky=W)

    root.bind('<Return>', callBack)
    root.mainloop()  


if __name__ == '__main__':
    main() 

Answer 1

The problem is that count cannot be seen by the callback() function. Trying replacing it with global count at the start of the main() function. This FAQ on global vars in Python should help.

def main():
    global count
    count = -1

    def callback(number):
        global count
        count = number + 1
        ...