tkinter - open file with button and save filename to variable

Question

I am trying to solve a problem that seems simple, but I cannot figure out how.
I want to create a simple program checking if a certain symbol exists in a text file:

1. The program starts;
2. The user clicks a button (inside the window, not in the menu);
3. A dialog box appears;
4. The user chooses a text file;
5. A message box displays the result;
6. The program closes.

Pretty straightforward, but I cannot find how to save the filename into a variable and then use it for the process. I read so many tutorials and I could not find a solution. Here is the code:

from tkinter import *
from tkinter import filedialog


def clicked():
    global filename
    filename = filedialog.askopenfile(filetypes=(("Word files","*.docx"),))


window = Tk()
window.geometry()
window.title("My App")
open_file_label = Label(window, text="Open your docx file here:", font=("Arial", 10), padx=5, pady=5)
open_file_label.grid(column=0, row=0)
open_file_button = Button(window, text="Click me", command=clicked, padx=5, pady=5)
open_file_button.grid(column=1, row=0)

window.mainloop()

Answer 1

filename is already a variable that contains the chosen file's contents. Just print(filename) and you'll get your data printed in console.