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How can I return a variable from a function that is opening a file using filedialog after selecting a tkinter button?

All of the tutorials I have seen deomonstrate the tkinter filedialog.askopenfilename function by only using the information collected within the function that is linked to the tkinter button. I can pass information in the function, but I would like to pass variables (filepath, images, etc.) outside the function and have them update variables in my GUI.
I have commented out the location I would like to call the variables in main_gui_setup function below. Any help will be appreciated, as it has been very demoralizing not being able to open a file. If this problem persists, my future as a programmer may be limited to creating tic-tac-toe games or instructional videos for Youtube.
from tkinter import *
import tkinter as tk
from tkinter import ttk
from tkinter import filedialog, messagebox
from PIL import ImageTk, Image # was import PIL.Image, PIL.ImageTk
import cv2
def main():
root = Tk()
window1 = Window(root, "X-ray Assist", "Give up")
return None
# can't pass by reference in python
class Window():
n = 0
file_path = ""
img1_info = ""
def __init__(self, root, title, message):
self.root = root
self.root.title(title)
#self.root.geometry(geometry)
self.screen_width = root.winfo_screenwidth()
self.screen_height = root.winfo_screenheight()
#self.root.attributes('-topmost', 1)
# SET APP WINDOW SIZE
scr_size_main = self.scr_size() # create instance of scr_size
self.root.geometry("%dx%d+%d+%d" % (self.root_width, self.root_height, self.root_x, self.root_y))
# CREATE MAIN WINDOW GUI
create_gui = self.main_gui_setup()
self.root.mainloop()
pass
def scr_size(self):
'''Reads monitor size and adjusts GUI frame sizes'''
self.root_width = int(self.screen_width*0.52)
self.root_height = int(self.screen_height*0.9)
self.root_x = int(self.screen_width*0.23)
self.root_y = int(self.screen_height*0.02)
self.img_ht_full = int(self.screen_height*0.82)
self.tools_nb_width = int(self.screen_width*0.22)
self.tools_nb_height = int(self.screen_height*0.48)
self.hist_nb_width = int(self.screen_width*0.22)
self.hist_nb_height = int(self.screen_height*0.23)
def open_image(self):
main_win = ttk.Frame(self.root)
main_win.grid(column=0, row=0)
self.file_path = filedialog.askopenfilename(initialdir='/', title='Open File',
filetypes=(('tif files', '*.tif'), ('all files', '*.*')))
self.file_path_label = ttk.Label(main_win, text=self.file_path)
self.file_path_label.grid(column=0, row=0, columnspan=1, sticky="nw", padx=(5,0), pady=1)
self.img1_8bit = cv2.imread(self.file_path, 0) #, cv2.IMREAD_ANYDEPTH | cv2.IMREAD_GRAYSCALE)
#self.img1_8bit_resize = cv2.resize(self.img1_8bit, (self.img_ht_full, self.img_ht_full)) #, interpolation = cv2.INTER_CUBIC)
#self.img1_height, self.img1_width = self.img1_8bit.shape # not resized for screen
#img1_info = text = f"{self.img1_height} {self.img1_8bit.dtype} {self.img1_16bit.dtype}"
#print(self.img1_width, " x ", self.img1_height, " bitdepth = ", self.img1_8bit.dtype)
#img1_info = ttk.Label
#print(f"{self.img1_height} {self.img1_width} {self.img1_8bit.dtype}")
#img1_info.grid(column=3, row=1, columnspan=1, sticky="w", padx=(5,0), pady=1)
#img = io.imread(main_win.filename) #scikit
self.img1_16bit = cv2.imread(self.file_path, cv2.IMREAD_ANYDEPTH | cv2.IMREAD_GRAYSCALE)
#self.img_canvas = tk.Canvas(self.root, width=self.img_ht_full, height=self.img_ht_full)
#self.img_canvas.grid(column=1, row=2, columnspan=10, rowspan=10, sticky="nw")
#self.img_canvas.image = ImageTk.PhotoImage(image=Image.fromarray(self.img1_8bit_resize))
#self.img_canvas.create_image(0,0, image=self.img_canvas.image, anchor="nw")
# .create_line(x1, y1, x2, y2, fill="color")
#self.img_canvas.create_line((self.img_ht_full/2), 0, (self.img_ht_full/2), (self.img_ht_full), fill="yellow")
#self.img_canvas.create_line(0, (self.img_ht_full/2), (self.img_ht_full), (self.img_ht_full/2), fill="yellow")
def main_gui_setup(self):
main_win = ttk.Frame(self.root)
main_win.grid(column=0, row=0)
image_win = ttk.Frame(main_win, borderwidth=25, relief="groove", width=self.img_ht_full, height=self.img_ht_full)
image_win.grid(column=1, row=2, columnspan=10, rowspan=10, sticky="nw")
toolbar = ttk.Frame(main_win, borderwidth=5) #, width=1100, height=15)
toolbar.grid(column=0, row=0, columnspan=10, rowspan=1, sticky="nw", padx=20)
hist_win = ttk.Frame(main_win, borderwidth=25, relief="groove", width=300, height=200)
panel_info = ttk.Label(main_win, text=f"{self.screen_width} x {self.screen_height}")
panel_info.grid(column=5, row=1, columnspan=1, sticky="e", pady=1)
# SCROLL SLIDER AT BOTTOM
slider = ttk.Scrollbar(main_win, orient="horizontal")
slider.grid(column=1, row=13, columnspan=7, padx=5, pady=5, sticky="ew")
#X-RAY AND DETECTOR SETTINGS - will input these from separate class
kv = ttk.Label(main_win, text="125kV")
kv.grid(column=0, row=2, columnspan=1, padx=15, pady=5)
file_path_label = ttk.Label(main_win, text="No image loaded")
file_path_label.grid(column=1, row=1, columnspan=1, sticky="nw", padx=(5,0), pady=1)
# CREATE BUTTONS
open = ttk.Button(toolbar, text="Open", width=10, command=self.open_image)
open.grid(column=0, row=0)
save = ttk.Button(toolbar, text="Save", width=10)
save.grid(column=1, row=0)
b1 = ttk.Button(toolbar, text="1", width=10)
b1.grid(column=2, row=0)
b2 = ttk.Button(toolbar, text="2", width=10)
b2.grid(column=3, row=0)
pass
main()

You aren't thinking of event driven programming correctly. In event driven programming you have callbacks to the functions you defined. Let's look at your code:
def get_path(self):
...
self.path_label = ...
...
def main_gui_setup(self):
main_win = ttk.Frame(self.root)
main_win.pack()
open = ttk.Button(main_win, text="Open", width=10, command=self.get_path)
open.pack()
# Problematic code:
# main_label = ttk.Label(main_win, self.path_label)
# main_label.pack()
When main_gui_setup is called it creates a frame and a button inside it. When the button is clicked it calls get_path which sets up the path_label variable. The problem that you were facing is that that as soon as you create your button (without waiting for the button to be pressed), you create the label called main_label.
For a simple fix to your problem try this:
def get_path(self):
...
self.file_path = ...
self.path_label = ...
...
def button_callback(self, main_win):
# set up
self.get_path()
# My guess is that you wanted `self.file_path` here instead of `self.path_label`
main_label = ttk.Label(main_win, self.file_path)
main_label.pack()
def main_gui_setup(self):
main_win = ttk.Frame(self.root)
main_win.pack()
# I am using a lambda and passing in `main_win` because you haven't
# assigned it to `self` using `self.main_win = ...`
open = ttk.Button(main_win, text="Open", width=10, command=lambda: self.button_callback(main_win))
open.pack()

I am still confused by what You are trying to accomplish:
from tkinter import Tk, Button, Label, filedialog
class MainWindow(Tk):
def __init__(self):
Tk.__init__(self)
self.open_file_btn = Button(self, text='Open', command=self.open_file)
self.open_file_btn.pack()
self.file_name = None
def open_file(self):
self.file_name = filedialog.askopenfilename()
Label(self, text=self.file_name).pack()
root = MainWindow()
root.mainloop()
I will explain what will happen here! (You can change the .askopenfilename() attributes obviously).
When the program opens the filedialog and You select a file, that file name will now get assigned to self.file_name and that variable can be used anywhere in the class.
also from what I have seen You should learn more about classes and PEP 8

Update text widget in tkinter from function

The problem:
I am trying to update the same text widget box from a function that contains some text. Instead a whole new text window appears every time.
Here is my code:
from tkinter import *
import os
#Tkinter graphics
homepage = Tk()
homepage.title("My first GUI")
# set size of window
homepage.geometry('1200x400')
# Add image file
bg = PhotoImage(file = "maxresdefault.png")
# Show image using label
label1 = Label( homepage, image = bg)
label1.place(x = 0, y = 0)
label2 = Label( homepage, text = "Test App")
label2.pack()
# Create Frame
frame1 = Frame(homepage)
frame1.pack()
#button initatiors
def buttonupdate():
S = Scrollbar(homepage)
T = Text(homepage, height=100, width=30)
T.pack()
T.pack(side=RIGHT, fill= Y)
S.pack(side = RIGHT, fill = Y)
S.config(command=T.yview)
T.insert(END, "test")
T.config(yscrollcommand=S.set, state=DISABLED)
# Static buttons
tickets30button = Button(text = "This is button 1", command=buttonupdate)
tickets30button.place(x=0, y=26)
mcibutton = Button(text = "This is button 2")
mcibutton.place(x=0, y=52)
hdebutton = Button(text = "This is button 3")
hdebutton.place(x=0, y=78)
homepage.mainloop()
Here is the result if I click on the first button three times:
Let me know if you have any suggestions that I can try.
Thank you for your time,

I was able to update my text window instead of create a new one, upon each click of a button, thanks to #TheLizzard.
He mentioned to move the section of code that creates the text window outside of the function and keep the section of code that creates the text, inside the function.
Before:
#button initiators
def buttonupdate():
S = Scrollbar(homepage)
T = Text(homepage, height=100, width=30)
T.pack()
T.pack(side=RIGHT, fill= Y)
S.pack(side = RIGHT, fill = Y)
S.config(command=T.yview)
T.insert(END, "test")
T.config(yscrollcommand=S.set, state=DISABLED)
After: (UPDATED)
S = Scrollbar(homepage)
T = Text(homepage, height=100, width=30)
T.pack(side=RIGHT, fill= Y)
S.pack(side = RIGHT, fill = Y)
S.config(command=T.yview)
T.config(yscrollcommand=S.set, state=DISABLED)
#button initatiors
def myTicketstatusbutton():
T.delete(1.0,END)
T.insert(END, "test")

problem with tkinter under defined function

Can you please help me with follwing issue I face:
When I am creating radiobutton with tkinter, I don't have a problem to select from the list.
However, if I put the same script under a menu, then selected option is always the default one, ("Python",1) in this specific case. Do you have any idea how to overcome this? Thanks in advance!
import tkinter as tk
root_m = tk.Tk()
root_m.geometry("400x200")
frame_m = tk.Frame(root_m)
root_m.title("NUMERIC UNIVERSE")
frame_m.pack()
def chars_merging():
languages = [
("Python",1),
("Perl",2),
("Java",3),
("C++",4),
("C",5)
]
root = tk.Tk()
root.geometry("400x200")
frame = tk.Frame(root)
root.title("SELECT SOMETHING")
frame.pack()
v = tk.IntVar()
v.set(0) # initializing the choice, i.e. Python
label = tk.Label(frame,
text="""Choose your favourite
programming language:""",
justify = tk.LEFT,
padx = 20)
label.pack()
def ShowChoice():
global data_sel
data_sel = v.get()
print(data_sel)
for val, language in enumerate(languages):
tk.Radiobutton(frame,
text=language,
indicatoron = 0,
width = 20,
padx = 20,
variable=data_sel,
command=ShowChoice,
value=val).pack(anchor=tk.W)
root.mainloop()
#return(languages[v.get()])
print("You selected", languages[v.get()])
button3 = tk.Button(frame_m,
text="3.Prepare and merge chars",
command=chars_merging,
width=25)
button3.pack()
# CLOSING THE WINDOW ---------------------------------------------------------
def finish():
root_m.destroy()
button_n = tk.Button(frame_m,
text="Finish",
command=finish,
width=25)
button_n.pack()
#------------------------------------------------------------------------------
#------------------------------------------------------------------------------
root_m.mainloop()

Making a Tkinter Listbox with Scrolll

I'm currently trying to make a Listbox with a Scroll bar on the side appear on my Tkinter Window. I can't figure out how to make the Scrollbar size the same size as my listbox. Heres my code:
global R3
global lb
R3 = Tk()
gg = "white"
g = "blue"
R3.geometry('720x720')
R3.title(username + " Dropbox")
R3.resizable(width=False, height=False)
logoutbt = Button(R3, text="Logout", width=10, height=2, bg=g, fg=gg, font="5", relief=RAISED, overrelief=RIDGE, command=rectologout)
upload = Button(R3, text="Upload", width=10, height=2, bg=g, fg=gg, font="5", relief=RAISED, overrelief=RIDGE, command=rectoupload)
logoutbt.place(x=220, y=500)
upload.place(x=480, y=500)
button1 = Button(R3, text='Receive file', width=10, height=2, bg=g, fg=gg, font="5", relief=RAISED, overrelief=RIDGE,command = get_file)
lb = Listbox(R3, height=6,width = 15)
s.send("RETREIVEA-"+username)
file_list = s.recv(1024).split("-")
if file_list == [""]:
button1.config(state = DISABLED)
for file in file_list:
lb.insert("end", file)
yscroll = Scrollbar(R3, orient=VERTICAL)
lb['yscrollcommand'] = yscroll.set
yscroll['command'] = lb.yview
lb.place(x=280,y=200)
yscroll.place(x=370,y=200)
button1.place(x=400, y=200)
R3.mainloop()
Any suggestions on how to do it?

First of all, please read how to create a Minimal, Complete and Verifiable example.
Your code lacks imports and references non-initialized objects / variables / functions.
How to achieve what you want?
Either use grid instead of place or pass height parameters to lb.place(..., height=<whatever you want>) and yscroll.place(..., height=<whatever you want>)

Tkinter blank window

I found this introductory tutorial online, but when I run it, I get just a blank window. Any idea what's going wrong?
# A more complex example showing the use of classes in GUI programming
from tkinter import *
class GUIExample:
def __init__(self, master):
self.master = master # for showInfo()
# Create frame to hold widgets
frame = Frame(master)
# Create label for header
self.headLbl = Label(frame, text="Widget Demo Program", relief=RIDGE)
self.headLbl.pack(side=TOP, fill=X)
# Dummy frame for border
spacerFrame = Frame(frame, borderwidth=10)
# Create frame to hold center part of the form
centerFrame = Frame(spacerFrame)
leftColumn = Frame(centerFrame, relief=GROOVE, borderwidth=10)
rightColumn = Frame(centerFrame, relief=GROOVE, borderwidth=10)
# Some colorful widgets
self.colorLabel = Label(rightColumn, text="Select a color")
self.colorLabel.pack(expand=YES, fill=X)
entryText = StringVar(master)
entryText.set("Select a color")
self.colorEntry = Entry(rightColumn, textvariable=entryText)
self.colorEntry.pack(expand=YES, fill=X)
# Create some radio buttons
self.radioBtns = []
self.radioVal = StringVar(master)
btnList = ("black", "red", "green", "blue", "white", "yellow")
for color in btnList:
self.radioBtns.append(Radiobutton(leftColumn, text=color, value=color, \
indicatoron=TRUE, variable=self.radioVal, command=self.updateColor))
else:
if (len(btnList) > 0):
self.radioVal.set(btnList[0])
self.updateColor()
for btn in self.radioBtns:
btn.pack(anchor=W)
# Make the frames visible
leftColumn.pack(side=LEFT, expand=YES, fill=Y)
rightColumn.pack(side=LEFT, expand=YES, fill=BOTH)
centerFrame.pack(side=TOP, expand=YES, fill=BOTH)
# Create an indicator checkbutton
self.indicVal = BooleanVar(master)
self.indicVal.set(TRUE)
self.updateIndic()
Checkbutton(spacerFrame, text="Show indicator", command=self.updateIndic, \
variable=self.indicVal).pack(side=TOP, fill=X)
# Create the Info button
Button(spacerFrame, text="Info", command=self.showInfo).pack(side=TOP, fill=X)
# Create the Quit button
Button(spacerFrame, text="Quit", command=self.quit).pack(side=TOP, fill=X)
def quit(self):
import sys
sys.exit()
def updateColor(self):
self.colorLabel.configure(fg=self.radioVal.get())
self.colorEntry.configure(fg=self.radioVal.get())
def updateIndic(self):
for btn in self.radioBtns:
btn.configure(indicatoron=self.indicVal.get())
def updateColorPrev(self):
if (self.colorprevVal.get()):
for btn in self.radioBtns:
color = btn.cget("text")
btn.configure(fg=color)
else:
for btn in self.radioBtns:
btn.configure(fg="black")
def showInfo(self):
toplevel = Toplevel(self.master, bg="white")
toplevel.transient = self.master
toplevel.title("Program info")
Label(toplevel, text="A simple Tkinter demo", fg="navy", bg="white").pack(pady=20)
Label(toplevel, text="Written by Bruno Dufour", bg = "white").pack()
Label(toplevel, text="http://www.cs.mcgill.ca/ ̃bdufou1/", bg="white").pack()
Button(toplevel, text="Close", command=toplevel.withdraw).pack(pady=30)
root = Tk()
ex = GUIExample(root)
root.title("A simple widget demo")
root.mainloop()

They forgot
frame.pack()
and
spacerFrame.pack()
I didn't test rest of code.
EDIT: BTW: In place of
def quit(self):
import sys
sys.exit()
I would use something more natural - and less drastic
def quit(self):
self.master.destroy()