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Using a class to create instances of Tkinter Toplevel() windows - Printable Version

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Using a class to create instances of Tkinter Toplevel() windows - nortski - Mar-27-2018

I'm a newbie at python and coding in general. I am messing around with Tkinter, trying to understand it. Before I go any further can someone tell me if it's ok practice to create a class to initialise Toplevel() windows?

This is my code, please pull it to pieces:

from tkinter import *

class TopLevelWindow():
    def __init__(self, master, width, height):
        self.master = master
        self.master.geometry("%sx%s+100+100" % (width, height))
        self.master.title("Toplevel Window")


root = Tk()
top1 = Toplevel()
top2 = Toplevel()
TopLevelWindow(top1, "300", "300")
TopLevelWindow(top2, "500", "250")

root.mainloop()
This code works but I really don't know what is happening, I just throw a few keywords together until it worked.
Can someone explain what is happening here where I pas in master and then define self.master as master. Is it even ALLOWED to be a master?

def __init__(self, master, width, height):
    self.master = master



RE: Using a class to create instances of Tkinter Toplevel() windows - Larz60+ - Mar-27-2018

self is an instance of itself, in your case TopLevelWindow
when you call __init__, you are passing top1 which is an instance of TopLevel, width of 300, and height of 300.

If you passed root instead of top1, there would only be one window.
you can also 'hide' the root window with root.withdraw()

Toplevel creates a new 'root like' window in addition to root

Once top1 is passed to TopLevelWindow, it becomes self.master or TopLevelWindow.master, but it's still the same instance of top1

Then you create yet another instance of TopLevelWindow passing top2 as master

you could of also instantiated TopLevelWindow this way, which may explain a bit more:
TopLevelWindow(master=top1, width="300", height="300")
I try to do this by default, but when cranking out code, often miss doing it. It explains what's what with a single glance.


RE: Using a class to create instances of Tkinter Toplevel() windows - nortski - Mar-27-2018

(Mar-27-2018, 11:12 AM)Larz60+ Wrote: self is an instance of itself, in your case TopLevelWindow
when you call __init__, you are passing top1 which is an instance of TopLevel, width of 300, and height of 300.

If you passed root instead of top1, there would only be one window.
you can also 'hide' the root window with root.withdraw()

Toplevel creates a new 'root like' window in addition to root

Once top1 is passed to TopLevelWindow, it becomes self.master or TopLevelWindow.master, but it's still the same instance of top1

Then you create yet another instance of TopLevelWindow passing top2 as master

you could of also instantiated TopLevelWindow this way, which may explain a bit more:
TopLevelWindow(master=top1, width="300", height="300")
I try to do this by default, but when cranking out code, often miss doing it. It explains what's what with a single glance.

Hi Larz, thank you very much for the explanation. I think the main thing that's important here is that this seems a legitimate way of creating multi toplevel windows without breaking anything else in Python haha

I can now move forward with my project.

Big Grin