Python Tkinter

Tkinter is Python’s built-in library for creating graphical user interfaces (GUIs). It acts as a lightweight wrapper around Tcl/Tk GUI toolkit, offering Python developers a simple and intuitive way to build desktop applications. It supports layout management, event handling and customization, making it ideal for rapid GUI development in Python.

Create First Tkinter GUI Application

There are two main methods used which user needs to remember while creating the Python application with GUI. These methods are:

1. Tk()

In Tkinter, the Tk() class is used to create the main application window. Every Tkinter program starts by creating exactly one Tk() object. Below is the syntax:

root = Tk(screenName=None, baseName=None, className='Tk', useTk=1)

Parameter:

• screenName (optional): Specifies the display (mainly used on Unix systems with multiple screens).
• baseName (optional): Sets the base name for the application (default is the script name).
• className (optional): Defines the name of the window class (used for styling and window manager settings).
• useTk (optional): A boolean that tells whether to initialize the Tk subsystem (usually left as default 1).

2. mainloop()

The mainloop() method starts the event loop of a Tkinter application. It keeps the window open, waits for user actions (like mouse clicks or key presses), and processes events until the window is closed. Below is the syntax:

root.mainloop()

Example: This example creates a basic Tkinter window and starts the event loop.

import tkinter as tk

root = tk.Tk()
# Widgets are added here

root.mainloop()

Output

Explanation:

• tk.Tk(): Creates the main application window.
• root.mainloop(): Starts the event loop and keeps the window responsive.
• The program stops only when the window is closed.

Tkinter Widget

There are a number of tkinter widgets which we can put in our tkinter application. Some of the major widgets are explained below:

1. Label

The Label widget is used to display text or images in a Tkinter window. It is commonly used for showing messages, titles, or instructions. Below is the syntax:

label = tk.Label(master, option=value)

Parameter: master refers to the parent window or container in which the label is placed.

Example: This example creates a simple window and displays a text label.

import tkinter as tk

root = tk.Tk()
label = tk.Label(root, text="GeeksForGeeks.org!")
label.pack()

root.mainloop()

Output

Explanation: label.pack() places the label inside the window.

Note: Tkinter widgets support many options such as font, bg (background) and fg (foreground). Only a few commonly used options are shown in the examples.

2. Button

The Button widget is a clickable component used to perform an action when pressed, such as submitting data or closing a window. Below is the syntax:

button = tk.Button(master, option=value)

Example: This example creates a window titled “Counting Seconds” with a Stop button. When the button is clicked, the application closes.

import tkinter as tk

root = tk.Tk()
root.title("Counting Seconds")

button = tk.Button(root, text="Stop", width=25, command=root.destroy)
button.pack()

root.mainloop()

Output

Explanation:

• tk.Button(): Creates a button widget.
• command=root.destroy: Closes the application when the button is clicked.
• button.pack(): Places the button in the window.

3. Entry

The Entry widget is used to accept single-line text input from the user. For multi-line text input, the Text widget is used instead. Below is the syntax:

entry = tk.Entry(master, option=value)

Example: This example creates a simple form with First Name and Last Name input fields. The grid() geometry manager is used to arrange labels and entry boxes in a table-like layout.

import tkinter as tk

root = tk.Tk()

tk.Label(root, text="First Name").grid(row=0, column=0)
tk.Label(root, text="Last Name").grid(row=1, column=0)

entry1 = tk.Entry(root)
entry2 = tk.Entry(root)

entry1.grid(row=0, column=1)
entry2.grid(row=1, column=1)

root.mainloop()

Output

Explanation:

• tk.Entry(): Creates a single-line text input box.
• grid(): Arranges widgets in rows and columns.

4. CheckButton

The Checkbutton widget is used to create a checkbox that can be toggled on or off. It is usually linked to a variable to store its current state. Below is the syntax:

check = tk.Checkbutton(master, option=value)

Example: This example creates a window with two checkboxes labeled Male and Female. Each checkbox is connected to an IntVar() that stores its state (1 for checked, 0 for unchecked).

import tkinter as tk

root = tk.Tk()

var1 = tk.IntVar()
var2 = tk.IntVar()

tk.Checkbutton(root, text="Male", variable=var1).grid(row=0, sticky=tk.W)
tk.Checkbutton(root, text="Female", variable=var2).grid(row=1, sticky=tk.W)

root.mainloop()

Output

Explanation:

• tk.IntVar(): Stores the checkbox state (1 or 0).
• grid(): Aligns widgets in rows and columns.
• sticky=tk.W: Aligns the checkbox to the left.

5. Radiobutton

The Radiobutton widget allows the user to select exactly one option from a group of choices. All radio buttons in a group share the same variable. Below is the syntax:

radio = tk.Radiobutton(master, option=value)

Example: This example creates two radio buttons labeled A and B. Only one option can be selected at a time.

import tkinter as tk

root = tk.Tk()
v = tk.IntVar()

tk.Radiobutton(root, text="A", variable=v, value=1).pack(anchor=tk.W)
tk.Radiobutton(root, text="B", variable=v, value=2).pack(anchor=tk.W)
root.mainloop()

Output

Explanation:

• tk.Radiobutton(): Creates a radio button widget.
• tk.IntVar(): Stores the selected option value.
• value: Assigned value when the radio button is selected.
• anchor=tk.W: Aligns buttons to the left.

6. Listbox

The Listbox widget displays a list of items from which the user can select one or more options. Below is the syntax:

listbox = tk.Listbox(master, option=value)

Example: This example displays a list of programming languages using a Listbox.

import tkinter as tk

root = tk.Tk()

lb = tk.Listbox(root)
lb.insert(1, "Python")
lb.insert(2, "Java")
lb.insert(3, "C++")
lb.insert(4, "Any other")

lb.pack()
root.mainloop()

Output

Explanation:

• tk.Listbox(): Creates a list container.
• insert(): Adds items to the listbox.
• pack(): Displays the listbox in the window.

7. Scrollbar

The Scrollbar widget provides a scrolling mechanism for widgets such as Listbox, Text, or Canvas. It is used when the content is larger than the visible area. Below is the syntax:

scrollbar = tk.Scrollbar(master, option=value)

Example: This example creates a Listbox with 100 items and attaches a vertical scrollbar to it.

import tkinter as tk

root = tk.Tk()

scrollbar = tk.Scrollbar(root)
scrollbar.pack(side=tk.RIGHT, fill=tk.Y)

mylist = tk.Listbox(root, yscrollcommand=scrollbar.set)

for line in range(100):
    mylist.insert(tk.END, "This is line number " + str(line))

mylist.pack(side=tk.LEFT, fill=tk.BOTH)
scrollbar.config(command=mylist.yview)

root.mainloop()

Output

Explanation:

• tk.Scrollbar(): Creates a vertical scrollbar.
• yscrollcommand=scrollbar.set: Connects the listbox to the scrollbar.
• scrollbar.config(command=mylist.yview): Enables scrolling behavior.
• pack(side, fill): Positions the widgets correctly.

8. Menu

The Menu widget is used to create menu bars and dropdown menus in a Tkinter application. Below is the syntax:

menu = tk.Menu(master, option=value)

Example: This example creates a menu bar with File and Help menus.

import tkinter as tk

root = tk.Tk()

menu = tk.Menu(root)
root.config(menu=menu)

filemenu = tk.Menu(menu)
menu.add_cascade(label="File", menu=filemenu)
filemenu.add_command(label="New")
filemenu.add_command(label="Open...")
filemenu.add_separator()
filemenu.add_command(label="Exit", command=root.quit)

helpmenu = tk.Menu(menu)
menu.add_cascade(label="Help", menu=helpmenu)
helpmenu.add_command(label="About")

root.mainloop()

Output

Explanation:

• tk.Menu(): Creates a menu container.
• add_cascade(): Adds dropdown menus to the menu bar.
• add_command(): Adds menu items.
• add_separator(): Adds a dividing line.
• root.config(menu=menu): Attaches the menu bar to the window.

9. Combobox

The Combobox widget (from tkinter.ttk) provides a drop-down list that allows users to select one value from a predefined set of options. Below is the syntax:

combo = ttk.Combobox(master, values=[...], state='readonly')

Example: This program creates a dropdown menu and displays the selected option in a label.

import tkinter as tk
from tkinter import ttk

def select(event):
    selected_item = combo_box.get()
    label.config(text="Selected Item: " + selected_item)

root = tk.Tk()
root.title("Combobox Example")

label = tk.Label(root, text="Selected Item:")
label.pack(pady=10)

# Create a Combobox widget
combo_box = ttk.Combobox(
    root,
    values=["Option 1", "Option 2", "Option 3"],
    state="readonly"
)
combo_box.pack(pady=5)

combo_box.set("Option 1")

combo_box.bind("<<ComboboxSelected>>", select)
root.mainloop()

Output

10. Scale

The Scale widget provides a graphical slider that allows users to select a numeric value from a given range. Below is the syntax:

scale = Scale(master, from_=min, to=max, orient=VERTICAL | HORIZONTAL)

Example: This example creates both vertical and horizontal sliders.

from tkinter import *

master = Tk()

# Vertical scale
vertical_scale = Scale(master, from_=0, to=42)
vertical_scale.pack()

# Horizontal scale
horizontal_scale = Scale(master, from_=0, to=200, orient=HORIZONTAL)
horizontal_scale.pack()

master.mainloop()

Output

Explanation:

• Scale(): Creates a slider widget.
• from_ / to: Defines the range of values.
• orient: Sets slider direction (VERTICAL or HORIZONTAL).
• pack(): Places the widget in the window.

11. TopLevel

The Toplevel widget is used to create a separate window in a Tkinter application. It is managed directly by the window manager and is commonly used for dialogs, pop-ups, or secondary windows. Below is the syntax:

top = Toplevel(master, option=value)

Example: This example creates a main window and a secondary window using Toplevel.

from tkinter import *
root = Tk()
root.title('GfG')
top = Toplevel()
top.title('Python')
top.mainloop()

Output

Explanation:

• Toplevel(): Creates a new independent window.
• title(): Sets the window title.

12. Message

The Message widget is used to display multi-line text with automatic word wrapping. It is useful for showing longer messages or descriptions in a formatted way.

message = Message(master, option=value)

Example: This example displays a text message with a colored background.

from tkinter import *

main = Tk()

ourMessage = "This is our Message"
messageVar = Message(main, text=ourMessage)
messageVar.config(bg="lightgreen")
messageVar.pack()

main.mainloop()

Output

Explanation:

• Message(): Creates a message widget with word wrapping.
• text: Specifies the message to display.
• config(bg=...): Sets background color.
• pack(): Places the widget in the window.

13. MenuButton

The Menubutton widget is used to create a button with a dropdown menu. When clicked, it displays a menu containing different options such as commands or checkbuttons. Below is the syntax:

menubutton = Menubutton(master, option=value)

Example: This example creates a Menubutton labeled GfG that opens a dropdown menu with two checkbutton options.

from tkinter import *
top = Tk() 
mb = Menubutton ( top, text = "GfG") 
mb.grid() 
mb.menu = Menu ( mb, tearoff = 0 ) 
mb["menu"] = mb.menu 
cVar = IntVar() 
aVar = IntVar() 
mb.menu.add_checkbutton ( label ='Contact', variable = cVar ) 
mb.menu.add_checkbutton ( label = 'About', variable = aVar ) 
mb.pack() 
top.mainloop() 

Output

Explanation:

• Menubutton(): Creates a button with an attached menu.
• Menu(): Defines the dropdown menu.
• add_checkbutton(): Adds toggleable options to the menu.
• IntVar(): Stores the checked/unchecked state.

14. Progressbar

The Progressbar widget is used to show the progress of a long-running task, such as file downloads or data processing. Below is the syntax:

Progressbar(parent, orient, length, mode)

Example: This example simulates a task by gradually filling the progress bar from 0% to 100% when a button is clicked.

import tkinter as tk
from tkinter import ttk
import time

def start_progress():
    progress.start()

    # Simulate a task that takes time to complete
    for i in range(101):
      # Simulate some work
        time.sleep(0.05)  
        progress['value'] = i
        # Update the GUI
        root.update_idletasks()  
    progress.stop()

root = tk.Tk()
root.title("Progressbar Example")

# Create a progressbar widget
progress = ttk.Progressbar(root, orient="horizontal", length=300, mode="determinate")
progress.pack(pady=20)

# Button to start progress
start_button = tk.Button(root, text="Start Progress", command=start_progress)
start_button.pack(pady=10)
root.mainloop()

Output:

15. SpinBox

The Spinbox widget is an enhanced Entry widget that allows users to select a value from a fixed range using up and down arrows. Below is the syntax:

spinbox = Spinbox(master, option=value)

Example: This example creates a Spinbox that allows selecting numbers from 0 to 10.

from tkinter import *

root = Tk()
root.title("Spinbox Example")

spinbox = Spinbox(root, from_=0, to=10)
spinbox.pack()

root.mainloop()

Output

Explanation:

• Spinbox(): Creates a numeric input field with increment/decrement arrows.
• from_ / to: Defines the allowed range.
• pack(): Places the widget in the window.

16. Text

The Text widget is used to display or edit multi-line text. Unlike Entry, it supports multiple lines and text formatting. Below is the syntax:

text = Text(master, option=value)

Example: This example creates a multi-line text box and inserts default text into it.

from tkinter import *

root = Tk()
root.title("Text Widget Example")

text_widget = Text(root, height=2, width=30)
text_widget.pack()

text_widget.insert(END, "GeeksforGeeks\nBEST WEBSITE\n")
root.mainloop()

Output

Explanation:

• Text(): Creates a multi-line text widget.
• insert(): Inserts text at a specified position.
• END: Appends text at the end.

17. Canvas

The Canvas widget is used to draw graphics, such as lines, shapes, text, and images. Below is the syntax:

canvas = Canvas(master, option=value)

Example: This example draws a horizontal line on a Canvas widget.

from tkinter import *

root = Tk()
root.title("Canvas Example")

canvas = Canvas(root, width=200, height=60)
canvas.pack()

y = 30
canvas.create_line(0, y, 200, y)
root.mainloop()

Output

Explanation:

• Canvas(): Creates a drawing area.
• create_line(): Draws a line using start and end coordinates.
• Canvas supports shapes, images, and custom graphics.

18. PanedWindow

The PanedWindow widget is a container that holds multiple widgets in resizable panes. Below is the syntax:

paned = PanedWindow(master, option=value)

Example: This example creates a PanedWindow with an Entry widget and a Scale widget arranged in resizable panes.

from tkinter import *

root = Tk()
root.title("PanedWindow Example")

paned_main = PanedWindow(root, orient=HORIZONTAL)
paned_main.pack(fill=BOTH, expand=1)

entry = Entry(paned_main, bd=5)
paned_main.add(entry)

paned_vertical = PanedWindow(paned_main, orient=VERTICAL)
paned_main.add(paned_vertical)

scale = Scale(paned_vertical, orient=HORIZONTAL)
paned_vertical.add(scale)

root.mainloop()

Output

Explanation:

• PanedWindow(): Creates a resizable container.
• add(): Adds widgets to panes.
• orient: Controls horizontal or vertical layout.
• Allows flexible and adjustable UI layouts.

Color Option in Tkinter

Tkinter widgets support various color options that allow you to customize their appearance, including:

• Background (bg) and Foreground (fg) colors
• Active background (activebackground) and active foreground (activeforeground) colors for buttons
• Selection colors for input fields

This example demonstrates different color options applied to Button, Label and Entry widgets.

import tkinter as tk

root = tk.Tk()
root.title("Color Options in Tkinter")

# Create a button with active background and foreground colors
button = tk.Button(root, text="Click Me", activebackground="blue", activeforeground="white")
button.pack()

# Create a label with background and foreground colors
label = tk.Label(root, text="Hello, Tkinter!", bg="lightgray", fg="black")
label.pack()

# Create an Entry widget with selection colors
entry = tk.Entry(root, selectbackground="lightblue", selectforeground="black")
entry.pack()

root.mainloop()

Output

Explanation:

• bg / fg: Sets default background and text color.
• activebackground/activeforeground: Colors applied when the button is pressed.
• selectbackground/selectforeground: Colors for text selection in Entry or Text widgets.

Learn more to Improve Font: Tkinter Font

Tkinter Geometry Managers

Tkinter provides geometry managers to control how widgets are arranged inside a window. The three main geometry managers are:

1. pack() method

The pack() method places widgets in blocks. One can control their position and whether they expand to fill the available space.

import tkinter as tk

root = tk.Tk()
root.title("Pack Example")

# Create three buttons
button1 = tk.Button(root, text="Button 1")
button2 = tk.Button(root, text="Button 2")
button3 = tk.Button(root, text="Button 3")

# Pack the buttons vertically
button1.pack()
button2.pack()
button3.pack()

root.mainloop()

Output

2. grid() method

The grid() method arranges widgets in a grid of rows and columns. Widgets can span multiple rows or columns using rowspan and columnspan.

import tkinter as tk

root = tk.Tk()
root.title("Grid Example")

# Create three labels
label1 = tk.Label(root, text="Label 1")
label2 = tk.Label(root, text="Label 2")
label3 = tk.Label(root, text="Label 3")

# Grid the labels in a 2x2 grid
label1.grid(row=0, column=0)
label2.grid(row=0, column=1)
label3.grid(row=1, column=0, columnspan=2)

root.mainloop()

Output

3. place() method

The place() method positions widgets at specific x and y coordinates. You can specify absolute or relative positions.

import tkinter as tk

root = tk.Tk()
root.title("Place Example")

# Create a label
label = tk.Label(root, text="Label")

# Place the label at specific coordinates
label.place(x=50, y=50)

root.mainloop()

Output

Event Handling in Tkinter

In Tkinter, events are actions that occur when a user interacts with the GUI, such as pressing a key, clicking a mouse button or resizing a window. Event handling allows us to define how our application should respond to these interactions.

Events and Bindings

Events in Tkinter are captured and managed using a mechanism called bindings. A binding links an event to a callback function (also known as an event handler) that is called when the event occurs. Below is the syntax:

widget.bind(event, handler)

• widget: The Tkinter widget you want to bind the event to.
• event: A string that specifies the type of event (e.g., <Button-1> for a left mouse click).
• handler: The callback function that will be executed when the event occurs.

Key and Mouse Events

Key events are triggered when a user presses a key on the keyboard. Mouse events are triggered by mouse actions, such as clicking or moving the mouse.

import tkinter as tk

def on_key_press(event):
    print(f"Key pressed: {event.keysym}")

def on_left_click(event):
    print(f"Left click at ({event.x}, {event.y})")

def on_right_click(event):
    print(f"Right click at ({event.x}, {event.y})")

def on_mouse_motion(event):
    print(f"Mouse moved to ({event.x}, {event.y})")

root = tk.Tk()
root.title("Advanced Event Handling Example")

root.bind("<KeyPress>", on_key_press)
root.bind("<Button-1>", on_left_click)
root.bind("<Button-3>", on_right_click)
root.bind("<Motion>", on_mouse_motion)

root.mainloop()

Output

Mouse moved to (182, 41)
Mouse moved to (141, 20)
Mouse moved to (134, 17)
Mouse moved to (128, 15)
Mouse moved to (125, 13)
Mouse moved to (122, 12)
Mouse moved to (120, 12)
Mouse moved to (119, 12)
Mouse moved to (117, 14)
Mouse moved to (117, 18)

Explanation:

• The on_mouse_motion function is called whenever the mouse moves in the window.
• Multiple event types can be handled at the same time.

Event Object

The event object is passed to the callback function when an event occurs. It contains useful information about the event, such as:

• event.keysym: The key symbol (e.g., 'a', 'Enter').
• event.x and event.y: The x and y coordinates of the mouse event.
• event.widget: The widget that triggered the event.