python EntryT

Prev Next

The Entry widget in Tkinter is used to create a single-line text box that allows users to input text. It is suitable for scenarios where only a single line of text input is needed. For multi-line text, the Text widget should be used.

Syntax:

w = Entry(parent, options)

Here, parent refers to the container widget (such as a window or frame), and options are used to configure the appearance and behavior of the Entry widget.

Options for Tkinter Entry:

SN	Option	Description
1	bg	Background color of the widget.
2	bd	Border width of the widget in pixels.
3	cursor	Changes the cursor type when over the Entry widget (e.g., arrow, dot).
4	exportselection	Determines if the text is automatically copied to the clipboard. Set to 0 to prevent copying.
5	fg	Foreground color (text color) of the Entry widget.
6	font	Font type used for the text in the Entry widget.
7	highlightbackground	Color of the highlight when the widget does not have focus.
8	highlightcolor	Color of the focus highlight rectangle around the widget.
9	highlightthickness	Width of the highlight rectangle around the widget when it has focus.
10	insertbackground	Color of the insertion cursor (caret).
11	insertborderwidth	Width of the 3-D border around the insertion cursor.
12	insertofftime	Duration (in milliseconds) that the insertion cursor remains off during blinking.
13	insertontime	Duration (in milliseconds) that the insertion cursor remains on during blinking.
14	insertwidth	Width of the insertion cursor.
15	justify	Alignment of the text if multiple lines are present (though Entry typically supports single line text).
16	relief	Type of the border around the widget (FLAT, RAISED, SUNKEN, GROOVE, RIDGE). Default is FLAT.
17	selectbackground	Background color of selected text.
18	selectborderwidth	Width of the border around selected text.
19	selectforeground	Font color of selected text.
20	show	Used to display text as a different character (e.g., * for passwords).
21	textvariable	A StringVar instance used to retrieve the text from the Entry widget.
22	width	Width of the Entry widget in characters.
23	xscrollcommand	Links the Entry widget to a horizontal scrollbar if needed.

Methods for Tkinter Entry:

SN	Method	Description
1	delete(first, last=None)	Deletes text from the specified range (first to last).
2	get()	Retrieves the text currently in the Entry widget.
3	icursor(index)	Sets the insertion cursor position to the specified index.
4	index(index)	Returns the index position of the specified character.
5	insert(index, s)	Inserts the specified string s before the character at the specified index.
6	select_adjust(index)	Adjusts the selection to include the character at the specified index.
7	select_clear()	Clears the current text selection.
8	select_from(index)	Sets the start index for text selection to the specified index.
9	select_present()	Returns True if any text is selected; otherwise False.
10	select_range(start, end)	Selects text in the range from start to end.
11	select_to(index)	Selects text from the start to the specified index.
12	xview(index)	Links the Entry widget to a horizontal scrollbar, setting its view to the specified index.
13	xview_scroll(number, what)	Scrolls the view of the Entry widget horizontally by number units, depending on what (UNITS or PAGES).

Example: A Simple Calculator

Here is an example of a basic calculator using the Entry widget:

from tkinter import *

def click(event):
    # Get the value from the entry widget
    entry_text = entry.get()
    # Evaluate the expression
    try:
        result = eval(entry_text)
        entry.delete(0, END)
        entry.insert(0, str(result))
    except Exception as e:
        entry.delete(0, END)
        entry.insert(0, "Error")

# Create the main window
root = Tk()
root.title("Simple Calculator")

# Create an entry widget for the input
entry = Entry(root, width=16, font=('Arial', 24), borderwidth=2, relief='solid')
entry.grid(row=0, column=0, columnspan=4)

# Create buttons
buttons = [
    '7', '8', '9', '/',
    '4', '5', '6', '*',
    '1', '2', '3', '-',
    '0', '.', '=', '+'
]

row_val = 1
col_val = 0

for button in buttons:
    Button(root, text=button, width=4, height=2, font=('Arial', 18),
        command=lambda b=button: entry.insert(END, b) if b != '=' else click(None)).grid(row=row_val, column=col_val)
    col_val += 1
    if col_val > 3:
        col_val = 0
        row_val += 1

# Run the application
root.mainloop()

Explanation of the Example:

• Entry Widget: Used to display and input text. It's where the user enters mathematical expressions.

• Buttons: Create a grid of buttons for digits and operators. Clicking a button inserts its value into the Entry widget. Clicking "=" evaluates the expression.

• Function: click() evaluates the expression entered in the Entry widget and displays the result.

This example demonstrates how to use the Entry widget in combination with buttons to create a simple calculator application.

Prev Next