{"id":1746,"date":"2020-12-21T07:01:16","date_gmt":"2020-12-21T07:01:16","guid":{"rendered":"https:\/\/www.pythontutorial.net\/?page_id=1746"},"modified":"2025-04-05T03:41:51","modified_gmt":"2025-04-05T03:41:51","slug":"tkinter-thread","status":"publish","type":"page","link":"https:\/\/www.pythontutorial.net\/tkinter\/tkinter-thread\/","title":{"rendered":"Tkinter Thread"},"content":{"rendered":"\r\n

Summary<\/strong>: In this tutorial, you’ll learn how to use multiple threads in Tkinter applications to make them more responsive.<\/p>\r\n\r\n\r\n\r\n

When to use Tkinter with Threads #<\/a><\/h2>\r\n\r\n\r\n\r\n

Let’s start with a simple program:<\/p>\r\n\r\n\r\n

import<\/span> tkinter as<\/span> tk\r\nfrom<\/span> tkinter import<\/span> ttk\r\nimport<\/span> time\r\n\r\n\r\ndef<\/span> task<\/span>()<\/span>:<\/span>\r\n    # Simulate a long-running task<\/span>\r\n    for<\/span> i in<\/span> range(5<\/span>):\r\n        print(f\"Task running... {i+1<\/span>}<\/span>\/5\"<\/span>)\r\n        time.sleep(1<\/span>)  \r\n\r\n    print(\"Task completed!\"<\/span>)\r\n\r\nroot = tk.Tk()\r\nroot.geometry(\"300x100\"<\/span>)\r\nroot.title(\"Tkinter Thread Example\"<\/span>)\r\n\r\nbutton = ttk.Button(root, text=\"Start Thread\"<\/span>, command=task)\r\nbutton.pack(pady=10<\/span>)\r\n\r\nroot.mainloop()<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\r\n\r\n\r\n
How it works.<\/p>\r\n\r\n\r\n\r\n
First, define the task()<\/code> function that takes 5 seconds to finish:<\/p>\r\n\r\n\r\n
def<\/span> task<\/span>()<\/span>:<\/span>\r\n    # Simulate a long-running task<\/span>\r\n    for<\/span> i in<\/span> range(5<\/span>):\r\n        print(f\"Task running... {i+1<\/span>}<\/span>\/5\"<\/span>)\r\n        time.sleep(1<\/span>)  \r\n\r\n    print(\"Task completed!\"<\/span>)<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\r\n\r\n\r\n
root = tk.Tk()\r\nroot.geometry(\"300x100\"<\/span>)\r\nroot.title(\"Tkinter Thread Example\"<\/span>)\r\n\r\nbutton = ttk.Button(\r\n    root, \r\n    text=\"Start Thread\"<\/span>, \r\n    command=task\r\n)\r\nbutton.pack(padx=10<\/span> ,pady=10<\/span>)\r\n\r\nroot.mainloop()<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\r\n\r\n\r\n
When you click the button, the program executes the task<\/code> function. During the function execution, the program freezes. It means that you cannot interact with the program by moving the window or clicking the button:<\/p>\r\n\r\n\r\n\r\n
\"\"<\/figure>\r\n\r\n\r\n\r\n
In Tkinter applications, the main loop should always start in the main thread. It handles events and updates the user interface (UI).<\/p>\r\n\r\n\r\n\r\n
If you have an operation that takes time, you should execute it in a separate thread<\/a>. To create and control multiple threads in Tkinter applications, you use the built-in threading<\/code><\/a> module.<\/p>\r\n\r\n\r\n\r\n
For more information on how to use the threading module, you can follow the Python threading tutorial<\/a>.<\/p>\r\n\r\n\r\n\r\n
The following program shows how to execute the task<\/code> function in a separate thread:<\/p>\r\n\r\n\r\n
import<\/span> tkinter as<\/span> tk\r\nfrom<\/span> tkinter import<\/span> ttk\r\nimport<\/span> time\r\nfrom<\/span> threading import<\/span> Thread\r\n\r\n\r\ndef<\/span> task<\/span>()<\/span>:<\/span>\r\n    # Simulate a long-running task<\/span>\r\n    for<\/span> i in<\/span> range(5<\/span>):\r\n        print(f\"Task running... {i+1<\/span>}<\/span>\/5\"<\/span>)\r\n        time.sleep(1<\/span>)  \r\n\r\n    print(\"Task completed!\"<\/span>)\r\n\r\ndef<\/span> handle_click<\/span>()<\/span>:<\/span>\r\n    t = Thread(target=task)\r\n    t.start()\r\n    \r\n\r\nroot = tk.Tk()\r\nroot.geometry(\"300x100\"<\/span>)\r\nroot.title(\"Tkinter Thread Example\"<\/span>)\r\n\r\nbutton = ttk.Button(\r\n    root, \r\n    text=\"Start Thread\"<\/span>, \r\n    command=handle_click\r\n)\r\nbutton.pack(padx=10<\/span> ,pady=10<\/span>)\r\n\r\nroot.mainloop()<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\r\n\r\n\r\n
How it works:<\/p>\r\n\r\n\r\n\r\n
from<\/span> threading import<\/span> Thread<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\r\n\r\n\r\n
Second, define a function handle_click<\/code> that creates a new thread and starts it:<\/p>\r\n\r\n\r\n
def<\/span> handle_click<\/span>()<\/span>:<\/span>\r\n    t = Thread(target=task)\r\n    t.start()<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\r\n\r\n\r\n
The new thread will execute the task<\/code> function.<\/p>\r\n\r\n\r\n\r\n
Third, bind the handle_click<\/code> function to the command of the button:<\/p>\r\n\r\n\r\n
button = ttk.Button(\r\n    root, \r\n    text=\"Start Thread\"<\/span>, \r\n    command=handle_click\r\n)<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\r\n\r\n\r\n
If you run the program and click the button, it will create two threads:<\/p>\r\n\r\n\r\n\r\n
First, import the Thread<\/a><\/code> class from the threading<\/code> module:<\/p>\r\n\r\n\r\n
Second, create a main window<\/a> with a button<\/a>:<\/p>\r\n\r\n\r\n