Using Tkinter in python to edit the title bar

Dan picture Dan · Mar 7, 2010 · Viewed 197k times · Source

I am trying to add a custom title to a window but I am having troubles with it. I know my code isn't right but when I run it, it creates 2 windows instead, one with just the title tk and another bigger window with "Simple Prog". How do I make it so that the tk window has the title "Simple Prog" instead of having a new additional window. I dont think I'm suppose to have the Tk() part because when i have that in my complete code, there's an error

from tkinter import Tk, Button, Frame, Entry, END

class ABC(Frame):
    def __init__(self,parent=None):
        Frame.__init__(self,parent)
        self.parent = parent
        self.pack()
        ABC.make_widgets(self)

    def make_widgets(self):
        self.root = Tk()
        self.root.title("Simple Prog")

Answer

Bryan Oakley picture Bryan Oakley · Mar 8, 2010

If you don't create a root window, Tkinter will create one for you when you try to create any other widget. Thus, in your __init__, because you haven't yet created a root window when you initialize the frame, Tkinter will create one for you. Then, you call make_widgets which creates a second root window. That is why you are seeing two windows.

A well-written Tkinter program should always explicitly create a root window before creating any other widgets.

When you modify your code to explicitly create the root window, you'll end up with one window with the expected title.

Example:

from tkinter import Tk, Button, Frame, Entry, END

class ABC(Frame):
    def __init__(self,parent=None):
        Frame.__init__(self,parent)
        self.parent = parent
        self.pack()
        self.make_widgets()

    def make_widgets(self):
        # don't assume that self.parent is a root window.
        # instead, call `winfo_toplevel to get the root window
        self.winfo_toplevel().title("Simple Prog")

        # this adds something to the frame, otherwise the default
        # size of the window will be very small
        label = Entry(self)
        label.pack(side="top", fill="x")

root = Tk()
abc = ABC(root)
root.mainloop()

Also note the use of self.make_widgets() rather than ABC.make_widgets(self). While both end up doing the same thing, the former is the proper way to call the function.