Skip files on button click [tkinter + Python 3.5] - python-3.x

Question

Suppose I have 'n' image files in a directory filedir which I want to view via tkinter console. Now, I want to skip a few files whenever necessary, using a button click event which invokes a function nextFile().
E.g.
import os
def nextFile():
global img
img_2 = process(img)
return img_2
window = tk.Tk()
window.title("File Viewer")
files = os.listdir(filedir)
button1 = tk.Button(window, text="Browse Files...", fg="black", command=askopenfilename)
button2 = tk.Button(window, text="SELECT", width=50, command=nextFile)
canvas = tk.Canvas(window, width=width, height=height)
button1.pack(side=tk.LEFT)
button2.pack(side=tk.BOTTOM)
canvas.pack()
for f in files:
img = cv2.cvtColor(cv2.imread(filedir + '/' + f), cv2.COLOR_BGR2RGB)
photo = ImageTk.PhotoImage(image=Image.fromarray((img))
canvas.create_image(0, 0, image=photo, anchor=tk.CENTER)
window.mainloop()
Any help is appreciated. Thanks!

Answer 1

Here is a simple example using PIL to load the inital image and then use a button and function to load each next image.
import tkinter as tk
from PIL import ImageTk, Image
import os
path = 'C:/your/file/path/here'
def nextFile():
# the global is needed to keep track of current index and also keep
# a reference of the image being displayed so its is not garbage collected.
global current_ndex, image
current_ndex += 1
if current_ndex < len(files):
img = Image.open('{}/{}'.format(path, files[current_ndex]))
image = ImageTk.PhotoImage(img)
# clear the canvas before adding the new image.
canvas.delete("all")
canvas.create_image(0, 0, image=image, anchor=tk.CENTER)
my_window = tk.Tk()
my_window.title("File Viewer")
files = os.listdir(path)
current_ndex = 0
button2 = tk.Button(my_window, text="Next", width=50, command=nextFile)
canvas = tk.Canvas(my_window, width=100, height=100)
button2.pack(side=tk.BOTTOM)
canvas.pack()
first_image = files[0]
img = Image.open('{}/{}'.format(path, first_image))
image = ImageTk.PhotoImage(img)
canvas.create_image(0, 0, image=image, anchor=tk.CENTER)
my_window.mainloop()