How to add an Image to a widget? Why is the image not displayed?

Question

How can I add an image to a widget in tkinter?

Why when I use this code it does not work:

some_widget.config(image=PhotoImage(file="test.png"), compound=RIGHT)

but this does work?:

an_image=PhotoImage(file="test.png")
some_widget.config(image=anImage, compound=RIGHT)

Solution

Your image is getting garbage collected when you try to use it in the first version.

effbot is ancient, but here's good snippet:

You must keep a reference to the image object in your Python program, either by storing it in a global variable, or by attaching it to another object.

In the second version the image is declared at the global level.

Here's another example that would demonstrate this issue, that you would expect to also work, after all it's the same code just in a function

Doesn't work:

import tkinter as tk
from PIL import ImageTk

root = tk.Tk()
def make_button():
    b = tk.Button(root)
    image = ImageTk.PhotoImage(file="1.png")
    b.config(image=image)
    b.pack()
make_button()
root.mainloop()

Does work:

import tkiner as tk
from PIL import ImageTk

root = tk.Tk()
def make_button():
    b = tk.Button(root)
    image = ImageTk.PhotoImage(file="1.png")
    b.config(image=image)
    b.image = image
    b.pack()
make_button()
root.mainloop()

Why? The variables in make_button are local to that function. Same idea if you run into this type of problem inside a class.