Python Tkinter GUI Tutorial #97: Threading with Tkinter

In this tutorial, we will be learning about threading with Tkinter in Python. Threading is a powerful way to keep your GUI responsive while performing time-consuming tasks in the background. Tkinter is a popular GUI toolkit for Python, and by combining it with threading, we can create more responsive and efficient applications.

To start off, make sure you have Tkinter installed on your system. Tkinter comes pre-installed with Python, so you should already have it. If not, you can install it using pip:

pip install tk

Now, create a new Python file and import the necessary modules:

import tkinter as tk
from tkinter import messagebox
import threading

Next, let’s create a simple Tkinter application with a button that performs a time-consuming task when clicked:

def long_task():
    # Simulate a time-consuming task
    for i in range(5):
        print("Task running...")
        time.sleep(1)
    print("Task completed!")

def on_click():
    # Start a new thread to perform the task
    thread = threading.Thread(target=long_task)
    thread.start()

root = tk.Tk()
root.title("Threading with Tkinter")

button = tk.Button(root, text="Start Task", command=on_click)
button.pack()

root.mainloop()

In this code, we have defined a long_task function that simulates a time-consuming task by printing messages every second. The on_click function starts a new thread to run the long_task function when the button is clicked.

Now, when you run the code and click the button, you will see the messages "Task running…" printed every second until the task is completed.

It’s important to note that Tkinter is not thread-safe, meaning that you should not update the GUI from a different thread than the main one. If you need to update the GUI from a thread, you can use the after method to schedule the update on the main thread:

def update_label(text):
    label.config(text=text)

def long_task():
    for i in range(5):
        update_label("Task running...")
        time.sleep(1)
    update_label("Task completed!")

root = tk.Tk()
root.title("Threading with Tkinter")

label = tk.Label(root, text="")
label.pack()

button = tk.Button(root, text="Start Task", command=on_click)
button.pack()

root.mainloop()

In this code, we have defined an update_label function that updates the label text. We call this function from the long_task function to update the label text on the main thread.

Threading with Tkinter can be a powerful tool to keep your GUI responsive while performing time-consuming tasks in the background. Just be sure to use threading carefully to avoid thread safety issues. Experiment with threading in your Tkinter applications and see how you can improve their performance and responsiveness.