Get the file path in global variable from browse button with tkinter

Question

I'm using tkinter. And I am trying to get a file path from a button and use it as an input for an other function. I defined filepathforinfo as a global variable, but I am not getting the expected result. I tried to follow the solution here.
Here is the main part of the code:

import tkinter.filedialog
import tkinter as tk

def get_pdf_file():
    global filepathforinfo #can be avoided by using classes
    filetypes=[('PDF files', '*.pdf')]
    filepathforinfo = tk.filedialog.askopenfilename(  title='Open a file',initialdir='/', filetypes=filetypes)



filepathforinfo='test'
    # Toplevel object which will
    # be treated as a new window
Information_Window = tk.Tk()
Information_Window.title("Information extraction")
Information_Window.resizable(True, True)
Information_Window['background']='#8c52ff'
info_button = tk.Button(Information_Window, text="Give the pdf file to extract information from", activebackground='purple',activeforeground='purple' ,command=get_pdf_file)
info_button.grid(row=0,column=0)
print(filepathforinfo)
#get_pdf_info(filepathforinfo)
    

Information_Window.mainloop()

After clicking the button and choosing the file, I get as an output only this :

Out[1]: 'test'

I dont know why I dont get the file path.

The closest answer I got is here, but it is still not satisfying.

The `filepathforinfo` variable's value will only be updated *while* the `mainloop()` running and the user clicks the button. See explanation of how GUIs work in [my answer}(https://stackoverflow.com/a/68928369/355230) to a question of which this is essentially a dup, — martineau, Aug 25 '21 at 18:58
@martineau Thanks for you answer, I checked your explanation, I understand the problem now. But I dont think I can use a Label in this case, because I dont want to show the text, I want to give to another function. — Anass, Aug 26 '21 at 00:20
Anass: You don't need to use a `Label` — the value of `filepathforinfo` does not have to be displayed anywhere. You just need to have this other function you want to pass the value to be invoked by some part of your GUI after the `get_pdf_file()` function has been run (or maybe as part of it running). The `print()` in your program doesn't work because at that point `get_pdf_file()` hasn't run yet — this was the main point I was trying to make by referring you to that other question. — martineau, Aug 26 '21 at 00:53

score 0 · Answer 1 · answered Aug 25 '21 at 18:55

The problem is your printing filepathforinfo before its even changed. I created a label to show it as it actually works.

import tkinter.filedialog
import tkinter as tk

def get_pdf_file():
    global filepathforinfo
    filetypes=[('PDF files', '*.pdf')]
    filepathforinfo = tk.filedialog.askopenfilename(  title='Open a file',initialdir='/', filetypes=filetypes)
    info_label['text'] = filepathforinfo

filepathforinfo='test'
    # Toplevel object which will
    # be treated as a new window
Information_Window = tk.Tk()
Information_Window.title("Information extraction")
Information_Window.resizable(True, True)
Information_Window['background']='#8c52ff'
info_button = tk.Button(Information_Window, text="Give the pdf file to extract information from", activebackground='purple',activeforeground='purple' ,command=get_pdf_file)
info_button.grid(row=0,column=0)

info_label = tk.Label(Information_Window, text= filepathforinfo)
info_label.grid()

Information_Window.mainloop()

Get the file path in global variable from browse button with tkinter

1 Answers1