How to access/use variables in methods defined in a Mixin class? - class

Question

I'm trying to break a tkinter app with several classes into multiple .py files. I'm using a Mixin class to import methods into each class. However, I'm struggling to access variables.
main.py contains a class creating the main window with a button to open a top level window and a button to get a variable from the Mixin.
# main.py
import tkinter
from tkinter import Tk
import customtkinter
import sys
sys.path.insert(1, "path/Classes")
from Classes import topLevel
# Main Window
class App(customtkinter.CTk):
def __init__(self):
super().__init__()
# Top Level Button
self.topLevel_button = customtkinter.CTkButton(master=self,
text="Open",
command=self.openTopLevel)
self.topLevel_button.grid(row=0, column=0)
# Get Variable
self.get_button = customtkinter.CTkButton(master=self,
text="Get Variable",
command=self.getVariable)
self.get_button.grid(row=1, column=0)
def openTopLevel(self):
window = topLevel.topLevel(self)
def getVariable(self):
print(var) # Can't access var
if __name__ == "__main__":
app = App()
app.mainloop()
topLevel.py is a class creating the top level window. It contains a variable fileSep to be used by a method in the Mixin Class:
# topLevel.py
sys.path.insert(1, "path/Methods")
from Methods import _topLevel
class topLevel(customtkinter.CTkToplevel, _topLevel.Mixin):
def __init__(self, parent):
super().__init__(parent)
# Create Variable
global fileSep
fileSep = customtkinter.StringVar(value="Comma")
print("Inside Class: " + fileSep.get()) # Works
# Create Button
self.loadButton = customtkinter.CTkButton(master=self,
text="Load",
command=self.loadFile)
self.loadButton.grid(row=0, column = 0, sticky='nswe')
# Attempt to access variable
def access_method(self):
print("Access Method: " + self.fileSep.get())
And _topLevel.py contains the mixin class:
# _topLevel.py
class Mixin:
def loadFile(self):
# Trying to access fileSep variable
print("Inside Mixin: " + fileSep.get()) # Error
topLevel().access_method() # Error
# I'm trying to access this variable from a function in main.py
var = "Hello World"
I get the following errors because the variables aren't accessible.
NameError: name 'var' is not defined
NameError: name 'fileSep' is not defined
I've tried making variables global as well as creating methods inside the class ( access_method() ) to print the variables as described here https://www.geeksforgeeks.org/python-using-variable-outside-and-inside-the-class-and-method/, but get the error:
TypeError: __init__() missing 1 required positional argument: 'parent'
How do I access variables that are defined in a class in the Mixin class? How would I access a variable created by the loadFile function in the Mixin Class for use in methods in the class App?

Answer 1

Thanks to #acw1668 comment, I just needed to make fileSep an instance variable:
self.fileSep = customtkinter.StringVar(value="Comma")
And to access it in the mixin class:
print("Inside Mixin: " + self.fileSep.get())
Equally I could create an instance variable to assign variable var to. For example in the topLevel class I added:
self.a = ""
And then assigned var to this variable within the function:
var = "Hello World"
self.a = var