Python Tkinter - Entry Widget

The Entry widget in Python's Tkinter module is used to accept single-line text input from the user. It's commonly used in forms, login interfaces, and other applications where textual input is required.

Syntax

entry = tk.Entry( root, options,... )

Common Options

Option	Description
width=30	Width in characters
font=("Helvetica",14)	The font and size used for the text
fg='gray'	Text color
bg='lightyellow'	Background color
bd=3	Border thickness
relief='sunken'	Border style
justify='left'	left,center,or right
show=' '	Masks input (e.g., for passwords: show="*" )
textvariable=text_var	Link to StringVar
validate='key'	Validate on every keystroke
validatecommand=validate_func	Validation function

The following example shows, how to create an Entry widget, retrieve the text entered by the user, and clear the Entry.

Example

import tkinter as tk
from tkinter import *

def get_entry():
    entered_text = var.get()
    print("Entered text : ", entered_text)

def clear_entry():
    var.set("") #or var.set("New Text")
    
root = tk.Tk()
root.title("Entry Widget Example")

#Create Tkinter variable and linked to Entry widgets
var = tk.StringVar()

# Create an Entry widget
entry = tk.Entry(root, textvariable = var)
entry.pack(padx=10,pady=10,side = LEFT)

#disable the entry
#entry.config(state='disabled')

#make it readonly
#entry.config(state='readonly')

# Create a button to get the Entry text
button = tk.Button(root, text="Show Entry", command=get_entry)
button.pack(padx=10,pady=10,side = LEFT)

# Create a button to Clear the Entry text
button = tk.Button(root, text="Clear", command=clear_entry)
button.pack(padx=10,pady=10,side = LEFT)

root.mainloop()

Output:

Example 2: Events

In Tkinter, you can bind key events to widgets (like Entry, Text, or the main Tk window) to respond when a user presses a key.

Example

import tkinter as tk

root = tk.Tk()

# Validation function: allows only digits or empty string
def on_focus_in(event):
    print("Entry is focused")
    
def on_focus_out(event):
    print("Entry lost focus")
    
def on_key_release(event):
    print("Key Released")
    
def on_key_press(event):
    print(f"Key pressed: {event.keysym}")
    
# Create Entry widget with validation
entry = tk.Entry(root)
entry.pack(pady=10)

entry.bind("<FocusIn>", on_focus_in)
entry.bind("<FocusOut>", on_focus_out)

# Bind the key release event to the Entry
entry.bind("<KeyRelease>", on_key_release)

# Bind key press to Entry
entry.bind("<KeyPress>", on_key_press)

root.mainloop()

Entry Validation

The following example shows, an Entry widget that only allows numeric input.

Example

import tkinter as tk

root = tk.Tk()

# Validation function: allows only digits or empty string
def only_numbers(value):
    return value.isdigit() or value == ""

# Register the validation command (%P - New proposed value of the Entry)
val_cmd = (root.register(only_numbers), "%P")

# Create Entry widget with validation
entry = tk.Entry(root, validate="key", validatecommand=val_cmd)
entry.pack(pady=10)

root.mainloop()