Updating image in label using python

Question

I have a python module that converts python's datetime.datetime.now() function to returns an image according to the number is sees. If it sees 01 seconds it returns two images one of 0 and one of 1. These are just jpg images. My python modules just resturns a dictionary like so:

{'am_pm': '{file_path}am.jpg', 'hour': '{file_path}five.jpg', 'second2': {file_path}one.jpg, 'second1': {file_path}zero.jpg, 'colon': '{file_path}Colon.jpg', 'minute2': '{file_path}zero.jpg', 'minute1': '{file_path}zero.jpg'}

I then have the following code in an attempt to display it in a label. Quite new to using tKinter though.

from PIL import ImageTk, Image
import datetime
from translator import Translator # my converter to get the above dict
import Tkinter as tk


def counter_label(label):
    def count():
        clock.get_time(datetime.datetime.now())
        image = clock.return_images() # this is the dict mentioned above
        label.configure(image=ImageTk.PhotoImage(Image.open(image['second2']))) # just using one entry in the dict for now.
        label.after(1000, count)
    count()


root = tk.Tk()
root.title("Counting Seconds")
label = tk.Label(root, fg="green")
label.pack()
clock = Translator()
counter_label(label)
button = tk.Button(root, text='Stop', width=25, command=root.destroy)
button.pack()
root.mainloop()

The code runs and I can see the label refresh, however I cannot see the jpg image in the label. What am I doing wrong?

score 2 · Accepted Answer · answered Oct 25 '15 at 11:22

The issue is that you are not making your application hold a reference to the image object. Since you do -

label.configure(image=ImageTk.PhotoImage(Image.open(image['second2'])))

label does not hold a strong reference to the image object you create and send as value for image keyword argument to label.configure() . Hence, as soon as the above line is executed the image object is eligible for garbage collection (and does get garbage collected) , hence you do not see the image.

You would need to make your application/program hold a strong reference to your object. A very simple way to do that would be to use global variable to store the reference to the image. Example -

def counter_label(label):
    def count():
        global image_obj
        clock.get_time(datetime.datetime.now())
        image = clock.return_images() # this is the dict mentioned above
        image_obj = ImageTk.PhotoImage(Image.open(image['second2']))
        label.configure(image=image_obj) # just using one entry in the dict for now.
        label.after(1000, count)
    count()

Not particularly. This question is just a signpost to the linked duplicate. — TigerhawkT3, Oct 25 '15 at 12:15

Updating image in label using python

1 Answers1