2. tk Button

See: https://docs.python.org/3/library/tkinter.html#tkinter.Button
See: https://www.geeksforgeeks.org/python-creating-a-button-in-tkinter/

2.1. Usage

The tkinter.Button widget provides a button.
To create a button widget the general syntax is (assuming import via "import tkinter as tk"):
button_widget = tk.Button(parent, option=value)
parent is the window or frame object.
Options can be passed as parameters separated by commas.

2.2. Sample button

initial

../_images/button_simple.png

pressed

../_images/button_simple_pressed.png
The code below creates a button with customised colours. The button changes appearance while it is being pressed.
The button will not appear until it is placed in the window using a geometry manager such as pack(), grid() or place().
import tkinter as tk

root = tk.Tk()
root.title("Button Widget Example")
root.geometry("350x100")

# Creating a button with specified options
button = tk.Button(
    root,
    text="Button",
    fg="black",  # Text color
    bg="lightblue",  # Background color
    activebackground="blue",  # Background color when clicked
    activeforeground="white",  # Text color when clicked
    font=("Arial", 12),
    padx=10,
    pady=5,
    width=15,
)

button.pack(padx=20, pady=20)

root.mainloop()

Tasks

  1. Modify the code above to change the window title to "Button question," set the window size to 350x100, set the button text to "Click Me", a light gray background, black text color, a black background when clicked, white text when clicked, Arial font size 14, centered text alignment, a border width of 3, a height of 2, a hand-shaped cursor on hover, a raised border style, a sunken border style on hovering over the button, horizontal inside padding of 10, vertical inside padding of 5, a width of 15, and text wrapping after 50 pixels, and adjust the pack method to add padding of 20 pixels on all sides.

../_images/button_question.png

Modify the code above to change the window title to "Button question," set the window size to 350x100, set the button text to "Click Me", a light gray background, black text color, a black background when clicked, white text when clicked, Arial font size 14, centered text alignment, a border width of 3, a height of 2, a hand-shaped cursor on hover, a raised border style, a sunken border style on hovering over the button, horizontal inside padding of 10, vertical inside padding of 5, a width of 15, and text wrapping after 50 pixels, and adjust the pack method to add padding of 20 pixels on all sides.

import tkinter as tk

# Create a new window
root = tk.Tk()
# Set the title of the window
root.title("Button question")
# Set the size of the window
root.geometry("350x100")

button = tk.Button(
    root,
    # Set the text displayed on the button
    text="Click Me",
    # Set the background color of the button
    bg="lightgray",
    # Set the text color of the button
    fg="black",
    # Set the background color when the button is active (clicked)
    activebackground="black",
    # Set the text color when the button is active (clicked)
    activeforeground="white",
    # Set the font of the button text
    font=("Arial", 14),
    # Set the alignment of the text within the button
    anchor="center",
    # Set the border width of the button
    bd=3,
    # Set the height of the button
    height=2,
    # Set the cursor that appears when hovering over the button
    cursor="hand2",
    # Set the relief style of the button
    relief="raised",
    # Set the relief style of the button when hovering over the button
    overrelief="sunken",
    # Set the padding around the text inside the button (horizontal)
    padx=10,
    # Set the padding around the text inside the button (vertical)
    pady=5,
    # Set the width of the button
    width=15,
    # Set the maximum line length for the text before wrapping
    wraplength=50,
)


button.pack(padx=20, pady=20)

root.mainloop()

2.3. Methods

button_widget.invoke()
Calls the button's command callback as though the button had been clicked.
button_widget.flash()
Briefly flashes the button between its active and normal colours.
button_widget.config(option=value)
Changes one or more button options after the button has been created.

2.4. Parameter syntax

button_widget = tk.Button(parent, option=value)
parent is the window or frame object.
Options can be passed as parameters separated by commas.

Parameters:

activebackground
Syntax: button_widget = tk.Button(parent, activebackground="color")
Description: Sets the background color of the button when it is active or pressed.
Default: SystemButtonFace RGB: (240, 240, 240)
Example: button_widget = tk.Button(root, activebackground="lightblue")
activeforeground
Syntax: button_widget = tk.Button(parent, activeforeground="color")
Description: Sets the foreground (text) color of the button when it is active or pressed.
Default: SystemButtonText RGB: (0, 0, 0)
Example: button_widget = tk.Button(root, activeforeground="white")
anchor
Syntax: button_widget = tk.Button(parent, anchor="position")
Description: Determines where the text is positioned within the button. Position values are "center", "n", "s", "e", "w", "ne", "nw", "se", "sw".
Default: "center"
Example: button_widget = tk.Button(root, anchor="center")
background
bg
Syntax: button_widget = tk.Button(parent, bg="color")
Description: Sets the background color of the button.
Default: SystemButtonFace RGB: (240, 240, 240)
Example: button_widget = tk.Button(root, bg="blue")
bitmap
Syntax: button_widget = tk.Button(parent, bitmap="bitmap_name")
Description: Sets a bitmap to be displayed on the button.
Default: None
Example: button_widget = tk.Button(root, bitmap="error")
borderwidth
bd
Syntax: button_widget = tk.Button(parent, bd=width)
Description: Sets the width of the button's border.
Default: 2
Example: button_widget = tk.Button(root, bd=2)
command
Syntax: button_widget = tk.Button(parent, command=callback_function)
Description: Specifies the function to call when the button is clicked. Do not include parentheses after the function name.
Default: None
Example: button_widget = tk.Button(root, command=on_click)
compound
Syntax: button_widget = tk.Button(parent, compound="position")
Description: Specifies the relative position of the image and text on the button. Common values are "top", "bottom", "left", "right", "center".
Default: None
Example: button_widget = tk.Button(root, compound="left")
cursor
Syntax: button_widget = tk.Button(parent, cursor="cursor_type")
Description: Changes the mouse cursor when it hovers over the button.
Default: None
Example: button_widget = tk.Button(root, cursor="hand2")
Possible values include: - "arrow": Standard arrow cursor. - "circle": Small circle cursor. - "clock": Clock or watch cursor. - "cross": Crosshair cursor. - "dotbox": Dotted box cursor. - "exchange": Arrows pointing in opposite directions. - "fleur": Four-way arrow for moving. - "hand2": Hand cursor, commonly used to indicate a clickable item. - "heart": Heart-shaped cursor. - "man": Icon of a person. - "mouse": Cursor shaped like a mouse. - "pirate": Skull-and-crossbones cursor. - "plus": Plus sign cursor. - "shuttle": Shuttle or spaceship. - "sizing": Cursor for resizing. - "spider": Spider cursor. - "spraycan": Spray can cursor. - "star": Star-shaped cursor. - "target": Target or bullseye cursor. - "tcross": T-shaped crosshair cursor. - "umbrella": Umbrella cursor. - "wait": Hourglass or watch cursor. - "xterm": I-beam cursor, commonly used for text selection.
default
Syntax: button_widget = tk.Button(parent, default="state")
Description: Sets the default button state. State values are "normal", "active", "disabled".
Default: "disabled"
Example: button_widget = tk.Button(root, default="active")
disabledforeground
Syntax: button_widget = tk.Button(parent, disabledforeground="color")
Description: Sets the foreground (text) color of the button when it is disabled.
Default: SystemDisabledText RGB: (109, 109, 109)
Example: button_widget = tk.Button(root, disabledforeground="grey")
fg
foreground
Syntax: button_widget = tk.Button(parent, fg="color")
Description: Sets the foreground (text) color of the button.
Default: SystemButtonText RGB: (0, 0, 0)
Example: button_widget = tk.Button(root, fg="white")
font
Syntax: button_widget = tk.Button(parent, font=("font_name", size))
Description: Sets the font type and size of the button text.
Default: None; Default Font Family: Segoe UI; Default Font Size: 9
Example: button_widget = tk.Button(root, font=("Arial", 12))
height
Syntax: button_widget = tk.Button(parent, height=height_in_lines)
Description: Sets the height of the button in lines of text.
Default: None
Example: button_widget = tk.Button(root, height=2)
highlightbackground
Syntax: button_widget = tk.Button(parent, highlightbackground="color")
Description: Sets the color of the focus highlight when the button does not have focus.
Default: SystemButtonFace RGB: (240, 240, 240)
Example: button_widget = tk.Button(root, highlightbackground="black")
highlightcolor
Syntax: button_widget = tk.Button(parent, highlightcolor="color")
Description: Sets the color of the focus highlight when the button has focus.
Default: SystemWindowFrame RGB: (100, 100, 100)
Example: button_widget = tk.Button(root, highlightcolor="red")
highlightthickness
Syntax: button_widget = tk.Button(parent, highlightthickness=thickness)
Description: Sets the thickness of the focus highlight.
Default: 1
Example: button_widget = tk.Button(root, highlightthickness=1)
image
Syntax: button_widget = tk.Button(parent, image=image_object)
Description: Sets an image to be displayed on the button.
Default: None
Example: button_widget = tk.Button(root, image=my_image)
justify
Syntax: button_widget = tk.Button(parent, justify="alignment")
Description: Specifies how multiple lines of text are aligned. Alignment values are "left", "center", "right".
Default: "center"
Example: button_widget = tk.Button(root, justify="center")
overrelief
Syntax: button_widget = tk.Button(parent, overrelief="relief_type")
Description: Sets the border style while the mouse pointer is over the button. Common values are "raised", "sunken", "flat", "ridge", "solid", "groove".
Default: None
Example: button_widget = tk.Button(root, overrelief="raised")
padx
Syntax: button_widget = tk.Button(parent, padx=padding)
Description: Sets the horizontal padding inside the button.
Default: 1
Example: button_widget = tk.Button(root, padx=10)
pady
Syntax: button_widget = tk.Button(parent, pady=padding)
Description: Sets the vertical padding inside the button.
Default: 1
Example: button_widget = tk.Button(root, pady=5)
relief
Syntax: button_widget = tk.Button(parent, relief="relief_type")
Description: Sets the border style of the button. Common values are "flat", "raised", "sunken", "ridge", "solid", "groove".
Default: "raised"
Example: button_widget = tk.Button(root, relief="solid")
repeatdelay
Syntax: button_widget = tk.Button(parent, repeatdelay=delay_ms)
Description: Sets the delay in milliseconds before the button action repeats when held down.
Default: None
Example: button_widget = tk.Button(root, repeatdelay=500)
repeatinterval
Syntax: button_widget = tk.Button(parent, repeatinterval=interval_ms)
Description: Sets the interval in milliseconds between repeats when the button is held down.
Default: None
Example: button_widget = tk.Button(root, repeatinterval=100)
state
Syntax: button_widget = tk.Button(parent, state="state")
Description: Sets the state of the button. State values are "normal", "active", "disabled".
Default: "normal"
Example: button_widget = tk.Button(root, state="disabled")
takefocus
Syntax: button_widget = tk.Button(parent, takefocus=boolean)
Description: Determines whether the button can receive focus via the Tab key.
Default: None
Example: button_widget = tk.Button(root, takefocus=True)
text
Syntax: button_widget = tk.Button(parent, text="text")
Description: Sets the text displayed on the button.
Default: ""
Example: button_widget = tk.Button(root, text="Click Me")
textvariable
Syntax: button_widget = tk.Button(parent, textvariable=stringvar)
Description: Binds a StringVar variable to the button's text, allowing dynamic updates.
Default: None
Example: button_widget = tk.Button(root, textvariable=my_var)
underline
Syntax: button_widget = tk.Button(parent, underline=index)
Description: Specifies the index of the character in the text to underline.
Default: -1 (No underline)
Example: button_widget = tk.Button(root, text="Save", underline=1)
width
Syntax: button_widget = tk.Button(parent, width=width_in_chars)
Description: Sets the width of the button in characters.
Default: None
Example: button_widget = tk.Button(root, width=10)
wraplength
Syntax: button_widget = tk.Button(parent, wraplength=width_in_pixels)
Description: Specifies the width (in pixels) at which the text should wrap to the next line.
Default: 0 (No wrapping)
Example: button_widget = tk.Button(root, wraplength=100)

2.5. Default options

Code to get the defaults for each button option is below.
import tkinter as tk

root = tk.Tk()

widget = tk.Button(root)
widget_options = widget.keys()

for option in widget_options:
    print(f"{option}: {widget.cget(option)}")  # cget retrieves the current value of the option