Python/Tkinter quit button for stacked frames

Question

I'm planning on making a fairly complex GUI in Python using Tkinter for a senior project. I came across this link that provides a great structured way to go about handling switching between frames by stacking them.

I want to make a simple quit button that exits the program when pressed because the GUI I plan to make will not have the window frame around it to minimize, maximize or exit. If I add a function such as this:

def quit_program(self):

    self.destroy()

And I put that function below the show_frame function and then in another class call upon it like so:

button3 = tk.Button(self, text="Quit",
                        command=lambda: controller.quit_program)

It doesn't work. Why is that? And how would I go about making a quit button with this frame structure?

Jordan Mattiuzzo · Accepted Answer · 2018-03-01T02:14:02.300

I have taken your code, and I could see a few errors with it. With some manipulation, I have managed to make it work. This is the result:

import Tkinter as tk
root = tk.Tk()
button3 = tk.Button(text="Quit", command=lambda: quit_program())
def quit_program():
    root.destroy()
button3.pack()
root.mainloop()

Good luck!

Jordan.

----- EDIT -----

Sorry, I failed to read your question fully. Hopefully this will aid your endeavours.

I put Brian's code into a program, and I added the destroy function just as you said. I then added a button in the class StartPage, in the function __init__. It can be found here, with the name button3.

class StartPage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller
        label = tk.Label(self, text="This is the start page", 
font=controller.title_font)
        label.pack(side="top", fill="x", pady=10)

        button1 = tk.Button(self, text="Go to Page One",
                        command=lambda: 
controller.show_frame("PageOne"))
        button2 = tk.Button(self, text="Go to Page Two",
                        command=lambda: 
controller.show_frame("PageTwo"))
        button3 = tk.Button(self, text="Quit",
                        command=lambda: 
controller.quit_program())
        button1.pack()
        button2.pack()
        button3.pack()

My code ended up working perfectly, where when you press the button, it quits the program. I think you'll find that when you were calling on the quit_program function, you were calling it like: controller.quitprogram, where you should be adding in the parentheses after it, as it is a function, like: controller.quit_program(). I haven't seen what you have actually put into your code, but in your question, you did not include the parentheses in your call.

Hope this helps!

Jordan.

thanks for the reply, however it's not quite what I was looking for. I was trying to add a quit button to the code posted in the link. I understand your answer completely, but I was hoping for an answer as to why it wasn't working if I added it to the answer posted by Brain Oakley that I linked in my question. Sorry if I wasn't clear enough in my question, first post on stack overflow! — Seth Law, Mar 01 '18 at 01:58
You can dispose of the lambda: replace `command=lambda: controller.quit_program())`, with `command=controller.quit_program)` — Reblochon Masque, Mar 01 '18 at 02:34

score 1 · Answer 2 · answered Mar 01 '18 at 19:48

button3 = tk.Button(self, text="Quit",
                        command=lambda: controller.quit_program)

Doesn't make button3 to call anything as it lacks the call () syntax inside lambda. Replace it with:

button3 = tk.Button(self, text="Quit",
                        command=lambda: controller.quit_program())

or better yet with:

button3 = tk.Button(self, text="Quit",
                        command=controller.quit_program)

Additionally, If you want to make quit functionality, you can use quit method instead, as it will destroy all GUI as opposed to the object it's attached to like destroy does:

button3 = tk.Button(self, text="Quit",
                        command=controller.quit)

Python/Tkinter quit button for stacked frames

2 Answers2