How do I set a label to items in a list?

Question

First, every time I press the button and choose an option, I get the error:

TypeError: unsupported operand type(s) for &: 'NoneType' and 'NoneType'.

But it does what it is supposed to do. Is this a problem?

Second, I want the text in the 'Current_list_var' label to contain an item from 'Champion list'. Then, when I press the button and choose an option, the next item from the list should appear on the label.

How would I be able to do this?

import tkinter as tk
from tkinter import ttk
import tkinter.messagebox
TITLE_FONT = ("Helvetica", 18, "bold")


root = tk.Tk()
root.minsize(500, 400)

titel = tk.StringVar()
score_Dennis = tk.IntVar()
score_Jawa = tk.IntVar()
titel_score_var = tk.IntVar()
list_var = tk.IntVar()
counter_var = tk.IntVar()
champvar = tk.StringVar()
listvar = tk.IntVar()

# Frames
mainframe=tk.Frame(root).pack()
titel_frame = tk.Frame(mainframe)
titel_frame.pack()
score_frame = tk.Frame(mainframe)
score_frame.pack()

# Init
titel.set("")

if score_Jawa == 0:
    score_Jawa.set(score_Jawa)

if score_Dennis == 0:
    score_Dennis.set(score_Dennis)

champion_list = ['SomeItem', 'AnotherItem', 'AndAnotherItem']


# Functions
def popup():
    tkinter.messagebox.showinfo('Info', 'popup')

def titel_check():

    if score_Dennis.get() == score_Jawa.get():
        titel.set('Het staat gelijk!')
        titel_score_var.set('start een match')
    elif score_Jawa.get() > score_Dennis.get():
        titel.set("Jawa staat voor met: ")
        titel_score_var.set(score_Jawa.get() - score_Dennis.get())
    else:
        titel.set("Dennis staat voor met: ")
        titel_score_var.set(score_Dennis.get() - score_Jawa.get())


def Dennis_plus():
    score_Dennis.set(score_Dennis.get() +1)
    titel_check()
    counter_var.set(score_Dennis.get() + score_Jawa.get())
    return
def Jawa_plus():
    score_Jawa.set(score_Jawa.get() + 1)
    titel_check()
    counter_var.set(score_Dennis.get() + score_Jawa.get())
    return


def nieuwe_match():
    x = champion_list
    top = tk.Toplevel()
    global listvar
    top.title("Uitslag")
    top.minsize(100, 80)
    msg = tk.Message(top, text="Who won?")
    msg.pack()

    button_Jawa = tk.Button(top, text="Jawa", command=lambda:Jawa_plus() & top.destroy())
    button_Jawa.pack(side=tk.LEFT, pady=15, padx=10)

    button_Dennis = tk.Button(top, text="Dennis", command=lambda:Dennis_plus() & top.destroy())
    button_Dennis.pack(side=tk.RIGHT, pady=15, padx=10)

    return


# Layout

titel_label = tk.Label(titel_frame, textvariable=titel, font=TITLE_FONT)
titel_label.grid(row=0, column=0)
huidige_champ = tk.Label(score_frame, text="De gespeelde Champ is:", font=TITLE_FONT)
huidige_champ.grid(row=5, column=0)
current_list_var = tk.Label(score_frame, text=champvar.get(), font=TITLE_FONT) # the list variable
current_list_var.grid(row=5, column=1)
titel_score = tk.Label(titel_frame, textvariable=titel_score_var, font=TITLE_FONT)
titel_score.grid(row=0, column=1)

score_Dennis_label_text = tk.Label(score_frame, text="Dennis: ", font=TITLE_FONT).grid(row=1, column=1)
score_Dennis_label = tk.Label(score_frame, textvariable=score_Dennis, font=TITLE_FONT)
score_Dennis_label.grid(row=1, column=2,sticky=tk.W)

score_Jawa_label_text=tk.Label(score_frame, text="Jawa: ", font=TITLE_FONT).grid(row=1, column=3)
score_Jawa_label = tk.Label(score_frame, textvariable=score_Jawa, font=TITLE_FONT)
score_Jawa_label.grid(row=1, column=4)


next_match = ttk.Button(score_frame, command=nieuwe_match, text="Match gespeeld").grid(row=2, column=2)
totaal_score_label_text = tk.Label(score_frame, text="Aantal gespeelde matches", font=TITLE_FONT).grid(row=4, column=0)
totaal_score_label = tk.Label(score_frame, textvariable=counter_var, font=TITLE_FONT).grid(row=4, column=2)


root.mainloop()

score 0 · Accepted Answer · edited May 23 '17 at 12:17

Your first error TypeError: unsupported operand type(s) for &: 'NoneType' and 'NoneType' is occured because of your lambda function within button_Jawa and button_Dennis.

The syntax for lambda is: lambda <args>: <expression> , where expression must be a single expression not multiple expressions separated by semicolon, ampersand or whatever!

So here's a trick (bad trick, so I suggest you to write new function that contains thoose two functions):

# try to pass your functions as a list (:
button_Jawa = tk.Button(top, text="Jawa", command=lambda: [Jawa_plus(), top.destroy()])
button_Dennis = tk.Button(top, text="Dennis", command=lambda: [Dennis_plus(), top.destroy()])

Your second problem - You are using the champvar-variable incorrectly. To bind StringVar to Label widget use textvariable parameter instead of simple text like this:

current_list_var = tk.Label(score_frame, textvariable=champvar, font=TITLE_FONT) # the list variable

but in this case, to update your champvar, you need update your lambda-functions as well! So final lambdas looks like that:

button_Jawa = tk.Button(top, text="Jawa", command=lambda: [Jawa_plus(), top.destroy(), champvar.set("Jawa")])
button_Dennis = tk.Button(top, text="Dennis", command=lambda: [Dennis_plus(), top.destroy(), champvar.set("Dennis")])

Here I showed how to change champvar to Dennis / Java, how to change champvar to an item from the list - I leave this task to you. I think that by writing a separate function instead of lambda you will cope with this task.

And to be honest - you need a class to store all your variables! If you really want it without class and with global list - you need another variable to loop over list!

Something like this:

from itertools import cycle

listing = ['ok1', 'ok2', 'blablabla', 'okagain']
listing2 = ['cat', 'dog', 'crocodile']


def loop_over(iterable=None, change=False):
    # smth like static variable
    if (not hasattr(loop_over, 'pool') or change) and iterable is not None:
        loop_over.pool = cycle(iterable)

    if not change and hasattr(loop_over, 'pool'):
        return next(loop_over.pool)


def main():
    # set new list to cycle
    loop_over(listing, True)

    # loop over
    for i in range(0, 5):
        print(loop_over())

    # set another list to cycle
    loop_over(listing2, True)

    # loop over
    for i in range(0, 5):
        print(loop_over())


main()

or more straight:

from itertools import cycle

pool = cycle(['cat', 'dog', 'crocodile'])

for i in range(0, 5):
    print(next(pool))

Summary:

You don't really need a lambda, just put your functions into another one! There's only one reason for lambda as a command parameter - if you want pass arguments along with function itself.
Try to structure you application as class, look over here

How do I set a label to items in a list?

1 Answers1