I have a button in my GUI then after selecting a image file I want it to display in new window.

Code:

import tkinter as tk
from tkinter import *   
from tkinter import ttk
from tkinter import filedialog
import os
from PIL import Image, ImageTk  # Place this at the end (to avoid any conflicts/errors)window = tk.Tk()
a = Tk()def openimgfile():currdir = os.getcwd()name = filedialog.askopenfile(initialdir = currdir, title = "Select a Image", filetype = ( ("PNG", "*.png"), ("JPEG", "*.jpg;.*jpeg"), ("All files", "*.*") ) )                         a.title("Pattern Matching")
a.minsize(200,200)
button1 = Button(text="Open file",width = 10,height =10,command=openimgfile).pack()a.mainloop()

For this to work you need to initialize this in command function:

from tkinter import *
from tkinter import filedialog
from PIL import Image, ImageTk
import oswindow = Tk()def open_img_file():filename = filedialog.askopenfilename(initialdir=os.getcwd(), title="Select file", filetypes=(("png images", ".png"), ("all files", "*.*")))if not filename:return# setup new windownew_window = Toplevel(window)# get imageimage = ImageTk.PhotoImage(Image.open(filename))# load imagepanel = Label(new_window, image=image)panel.image = imagepanel.pack()window.title("Pattern Matching")
window.minsize(200, 200)
button = Button(text="Open file", width=10, height=10,command=open_img_file)
button.pack()window.mainloop()