How can I return a value from an function that is executed from tkinter button?

Question

Just started learning Python. I have created a file containing a class with tkinter fuctions.

For Example:

file1.py:

import tkinter as tk
import pandas as pd
import os
class flt:
    def func(var):
        var['file'] = pd.read_excel(os.getcwd()+'\\xyz.xlsx')
        if var[ch].get()==1:
            var['file'] = "Filter this file accordingly"   # Example
        if var[hc].get()==1:
            var['file'] = "filter this file accordingly"   #Example
        return var['file']     #I want this value in file2.py
    def do_something(var):
        root = var['root']
        mainframe = var['mainframe']
        var[ch] = IntVar()
        var[hc] = IntVar()
        ch1 = Checkbutton(mainframe, text='Filter by ABC',variable=var[ch])
        ch2 = Checkbutton(mainframe, text='Filter by 123', variable=var[ch])
        ch1.place(relx=0.4, rely=0.2)
        ch2.place(relx=0.4, rely=0.3)
        bt = tk.Button(mainframe, text='submit', command=lambda: flt.func(var))
        bt.place(relx=0.5, rely=0.5)

And the another file, say file2.py:

import tkinter as tk
root = tk.Tk()
mainframe = tk.Frame(root, relief='raised')
mainframe.place(relx=0.1, rely=0.1, width='1100', height='380')
val = {}
val['root'] = root
val['mainframe'] = mainframe
def chk:
    import file1
    value = file1.do_something(val)
    print(value)
btn = tk.Button(mainframe, text='Check', command = chk)
btn.place(relx=0.5, rely=0.8)
root.mainloop()

I want the value "var['file']" (from func(var)>file1.py) in file2.py Every Answer is appreciated. Thank you.

Answer 1

You keep making your code more and more complicated and I still don't understand what you want.

So, I made this minimal program to show that when its the case that a new button appears, and the user presses that button, that a value is calculated and used in a call to an arbitrary function from another module: file1.py

import tkinter as tk

def func(var):
    var['file'] = 42
    return var['file']

def do_something(var, f):
    # root = var['root']
    mainframe = var['mainframe']
    bt = tk.Button(mainframe, text='submit', command=lambda: f(func(var)))
    # When the user presses submit, the function f is called with the 'return' value
    bt.place(relx=0.5, rely=0.5)

file2.py

import tkinter as tk
root = tk.Tk()
mainframe = tk.Frame(root, relief='raised')
mainframe.place(relx=0.1, rely=0.1, width='1100', height='380')
val = {}
val['root'] = root
val['mainframe'] = mainframe

def f(value):
    print(value)   # Just prints the value, but could do anything!
    
def chk():
    import file1
    file1.do_something(val, f)  # f passed from here as a callback
    # Note - no return value

btn = tk.Button(mainframe, text='Check', command = chk)
btn.place(relx=0.5, rely=0.8)
root.mainloop()

Note: the frame starts small and you need to drag it to resize it bigger to see the buttons.

Answer 2

Here first you have to create the respective class and then import the file.

File1:

#creating a class
class person:
    def __init__ f1(self,x):# this function will be called everytime when the class is called
        self.value=x

File2:

import file1    #importing the file (file name)
x=file1.person(10)#calling the class from file1 (parameter given as 10)
print(x.value)  #printing the value.

---

In your case:

file 1:

import tkinter as tk
class flt:
    def __init__(self,x):
        self.value = x*x

    def do_something(self,var):
        #some stuff

file 2:

import file1
import tkinter as tk

#basic tkinter window code

trial=file1.flt('value')
test=trial.value #here you store the value of file1

def chk:
    value = file1.do_something(val)
    print(value)
btn = tk.Button(mainframe, text='Check', command = chk)
btn.place(relx=0.5, rely=0.8)
root.mainloop()