rys rys - 4 months ago 49
Python Question

Python tkinter - successfully inherit from toplevel

I am trying to use an object-oriented approach to create a class that inherits from tkinter's Toplevel, triggered by pressing a button in the main window.

The current code raises an AttributeError ('MakeWindow' object has no attribute 'tk'). Can anyone point me in the right direction?

#! python3
import tkinter as tk


class Application:
def __init__(self, master):
self.frame = tk.Frame(master)
self.frame.pack()
self.okButton = tk.Button(self.frame, text="OK",
command=self.window_maker).pack()
self.quitButton = tk.Button(self.frame, text="Close",
command=self.frame.quit).pack()
def window_maker(self):
MakeWindow("A message to Toplevel")


class MakeWindow(tk.Toplevel):
def __init__(self, message):
super().__init__(self)
self.message = message
self.display = tk.Label(self, text=message)
self.display.pack()


if __name__ == '__main__':
root = tk.Tk()
app = Application(root)
root.mainloop()


Full traceback:

Exception in Tkinter callback
Traceback (most recent call last):
File "C:\Users\richhart\AppData\Local\Programs\Python\Python35\lib\tkinter\__init__.py", line 1550, in __call__
return self.func(*args)
File "C:/Users/richhart/PycharmProjects/tkinter_gui/y.py", line 15, in window_maker
MakeWindow("A message to Toplevel")
File "C:/Users/richhart/PycharmProjects/tkinter_gui/y.py", line 20, in __init__
super().__init__(self)
File "C:\Users\richhart\AppData\Local\Programs\Python\Python35\lib\tkinter\__init__.py", line 2182, in __init__
BaseWidget.__init__(self, master, 'toplevel', cnf, {}, extra)
File "C:\Users\richhart\AppData\Local\Programs\Python\Python35\lib\tkinter\__init__.py", line 2132, in __init__
BaseWidget._setup(self, master, cnf)
File "C:\Users\richhart\AppData\Local\Programs\Python\Python35\lib\tkinter\__init__.py", line 2110, in _setup
self.tk = master.tk
AttributeError: 'MakeWindow' object has no attribute 'tk'

Answer

The problem is the super().__init__(self) it should be super().__init__(). Moreover, it is not necesssary to use super in this case (see How to use 'super' in Python?). The following code works:

import tkinter as tk


class Application:
    def __init__(self, master):
        self.frame = tk.Frame(master)
        self.frame.pack()    
        self.okButton = tk.Button(self.frame, text="OK",
                                  command=self.window_maker).pack()
        self.quitButton = tk.Button(self.frame, text="Close",
                                    command=self.frame.quit).pack()
    def window_maker(self):
        MakeWindow("A message to Toplevel")


class MakeWindow(tk.Toplevel):
    def __init__(self, message):
        tk.Toplevel.__init__(self) #instead of super
        self.message = message
        self.display = tk.Label(self, text=message)
        self.display.pack()


if __name__ == '__main__':
    root = tk.Tk()
    app = Application(root)
    root.mainloop()
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