Welcome folks today in this blog post we will be building image viewer tkinter app in python. All the full source code of the application is shown below.

Get Started

In order to get started you need to install the following library using the pip command as shown below

pip install tkinter

After installing this library make an app.py file and copy paste the following code

app.py

# importing the tkinter module and PIL 
# that is pillow module 
from tkinter import *
from PIL import ImageTk, Image 


def forward(img_no): 

    # GLobal variable so that we can have 
    # access and change the variable 
    # whenever needed 
    global label 
    global button_forward 
    global button_back 
    global button_exit 
    label.grid_forget() 

    # This is for clearing the screen so that 
    # our next image can pop up 
    label = Label(image=List_images[img_no-1]) 

    # as the list starts from 0 so we are 
    # subtracting one 
    label.grid(row=1, column=0, columnspan=3) 
    button_for = Button(root, text="forward", 
                        command=lambda: forward(img_no+1)) 

    # img_no+1 as we want the next image to pop up 
    if img_no == 4: 
        button_forward = Button(root, text="Forward", 
                                state=DISABLED) 

    # img_no-1 as we want previous image when we click 
    # back button 
    button_back = Button(root, text="Back", 
                        command=lambda: back(img_no-1)) 

    # Placing the button in new grid 
    button_back.grid(row=5, column=0) 
    button_exit.grid(row=5, column=1) 
    button_for.grid(row=5, column=2) 


def back(img_no): 

    # We willl have global variable to access these 
    # variable and change whenever needed 
    global label 
    global button_forward 
    global button_back 
    global button_exit 
    label.grid_forget() 

    # for clearing the image for new image to pop up 
    label = Label(image=List_images[img_no - 1]) 
    label.grid(row=1, column=0, columnspan=3) 
    button_forward = Button(root, text="forward", 
                            command=lambda: forward(img_no + 1)) 
    button_back = Button(root, text="Back", 
                        command=lambda: back(img_no - 1)) 
    print(img_no) 

    # whenever the first image will be there we will 
    # have the back button disabled 
    if img_no == 1: 
        button_back = Button(root, Text="Back", state=DISABLED) 

    label.grid(row=1, column=0, columnspan=3) 
    button_back.grid(row=5, column=0) 
    button_exit.grid(row=5, column=1) 
    button_for.grid(row=5, column=2) 


# Calling the Tk (The intial constructor of tkinter) 
root = Tk() 

# We will make the title of our app as Image Viewer 
root.title("Image Viewer") 

# The geometry of the box which will be displayed 
# on the screen 
root.geometry("700x700") 

# Adding the images using the pillow module which 
# has a class ImageTk We can directly add the 
# photos in the tkinter folder or we have to 
# give a proper path for the images 
image_no_1 = ImageTk.PhotoImage(Image.open("sample1.png")) 
image_no_2 = ImageTk.PhotoImage(Image.open("sample2.png")) 
image_no_3 = ImageTk.PhotoImage(Image.open("Sample3.png")) 
image_no_4 = ImageTk.PhotoImage(Image.open("sample4.png")) 

# List of the images so that we traverse the list 
List_images = [image_no_1, image_no_2, image_no_3, image_no_4] 

label = Label(image=image_no_1) 

# We have to show the the box so this below line is needed 
label.grid(row=1, column=0, columnspan=3) 

# We will have three button back ,forward and exit 
button_back = Button(root, text="Back", command=back, 
                    state=DISABLED) 

# root.quit for closing the app 
button_exit = Button(root, text="Exit", 
                    command=root.quit) 

button_forward = Button(root, text="Forward", 
                        command=lambda: forward(1)) 

# grid function is for placing the buttons in the frame 
button_back.grid(row=5, column=0) 
button_exit.grid(row=5, column=1) 
button_forward.grid(row=5, column=2) 

root.mainloop()

Now just replace the paths of all the four images in the above python script and then run the script by typing the below command

python app.py

As you can see in the gui app we have three buttons first is the forward button and the second is backward and the third one is quit button