photo-viewer

#photo viewer app
from tkinter import *
from PIL import ImageTk, Image
import os
root = Tk()
root.title("tkinter image viewer")
path="/home/pi/mu_code/tkinter/images" #change this to where the images are stored
images = os.listdir(path)  #creates a list of image file names
image_list=[]
#creates a list containing copies of the actual images... i think...
for i in range(len(images)):
    image_list.append(ImageTk.PhotoImage(Image.open(path+"/"+images[i])))

image_num=0
myLabel = Label(image=image_list[image_num])
myLabel.grid(row=0, column=0, columnspan=3)

def forward():
    global image_num
    global myLabel
    image_num += 1
    myLabel.grid_forget()
    myLabel = Label(image=image_list[image_num])
    myLabel.grid(row=0, column=0, columnspan=3)
    #the following code disables the forward button when we get to the last image in the list, 
    #and also re-enables the back button if it was disabled
    if len(image_list)-1 == image_num:
        button_forward = Button(root, text=">>", command=forward, state = DISABLED)
        button_forward.grid(row=2, column=2)
    else:
        button_back = Button(root, text="<<", command=back)
        button_back.grid(row=2, column=0)  

def back():
    global image_num
    global myLabel
    image_num -= 1
    myLabel.grid_forget()
    myLabel = Label(image=image_list[image_num])
    myLabel.grid(row=0, column=0, columnspan=3)
    #the following code disables the back button when we get to the last image in the list, 
    #and also re-enables the forward button if it was disabled
    if image_num == 0: #if at first photo, the back button needs to be disabled
        button_back = Button(root, text="<<", command=back, state = DISABLED)
        button_back.grid(row=2, column=0)
    else:
        button_forward = Button(root, text=">>", command=forward)
        button_forward.grid(row=2, column=2)

button_back = Button(root, text="<<", command=back, state = DISABLED) #starts at first picture so needs to be disabled
button_exit = Button(root, text="Exit", command=root.destroy)
button_forward = Button(root, text=">>", command=forward)

button_back.grid(row=2, column=0)
button_exit.grid(row=2, column=1)
button_forward.grid(row=2, column=2)

root.mainloop()