A concise way to configure tkinter option menu

The OptionMenu widget is a drop-down menu that displays a list of options for the user to choose from. It's a commonly used widget in graphical user interface (GUI) programming for Python, and is often used in conjunction with other Tkinter widgets to create intuitive and interactive interfaces.

In this article, we'll explore a concise way to configure the Tkinter OptionMenu widget using Python. Specifically, we'll cover −

• The basic syntax of the OptionMenu widget

• How to bind a command to the selection

• A concise way to define options and their corresponding commands

By the end of this article, you'll have a solid understanding of how to use the OptionMenu widget in your Python applications.

Basic Syntax of the OptionMenu Widget

The basic syntax for creating an OptionMenu widget in Tkinter is as follows −

OptionMenu(master, variable, *options)

• master is the parent widget

• variable is a StringVar object that holds the currently selected option

• *options are the options to display in the menu, separated by commas

Example

For example, let's create a basic OptionMenu that allows the user to select their favorite color −

from tkinter import *

root = Tk()
root.geometry("720x250")
root.title("Creating a basic OptionMenu Widget")

colors = ["Red", "Green", "Blue"]
selected_color = StringVar(value=colors[0])

color_menu = OptionMenu(root, selected_color, *colors)
color_menu.pack()

root.mainloop()

In this code, we define a list of colors and create a StringVar object called selected_color that holds the currently selected color (which is initially set to the first color in the list). We then create an OptionMenu called color_menu that displays the list of colors, using the selected_color variable to keep track of the current selection. Finally, we pack the OptionMenu onto the main window using the pack() method.

Output

When we run this code, we see a drop-down menu that displays the list of colors −

Binding a Command to the Selection

Often, we want to execute a function when the user selects an option from the OptionMenu. We can achieve this by binding a command to the OptionMenu using the command parameter in the constructor.

Example

For example, let's create an OptionMenu that displays a list of animals, and prints the selected animal to the console when the user selects it −

from tkinter import *

root = Tk()
root.geometry("720x250")
root.title("Creating a basic OptionMenu Widget with Binding a Command to the Selection")

def show_selection(option):
   print(f"Selected option: {option.get()}")

options = ["Cat", "Fish", "Dog"]
selected_option = StringVar(value=options[0])

option_menu = OptionMenu(root, selected_option, *options, command=lambda option: show_selection(selected_option))
option_menu.pack()

root.mainloop()

Output

When we run this code, we see the drop-down menu of animals −

And when we select an animal, we see the corresponding message printed to the console −

Selected option: Fish

A Concise Way to Define Options and Commands

In many cases, we may have a large number of options to display in an OptionMenu, along with corresponding commands to execute when each option is selected. In such cases, it can be cumbersome to define each option and command individually in the constructor.

Instead, we can use a dictionary to define the options and corresponding commands, and then use a loop to create the OptionMenu dynamically. Here's an example that demonstrates this approach −

Example

from tkinter import *

root = Tk()
root.geometry("720x250")
root.title("A Concise Way to Define Options and Commands in tkinter Option menu Widget")

def show_selection(option):
   print(f"Selected option: {option.get()}")

options = ["Option1", "Option2", "Option3", "Option4", "Option5"]
selected_option = StringVar(value=options[0])

option_menu = OptionMenu(root, selected_option, *options, command=lambda option: show_selection(selected_option))
option_menu.pack()

root.mainloop()

In this code, we define a dictionary called options that maps each option label to a corresponding lambda function that executes the desired command. We also define a selected_option variable that holds the currently selected option, which is initially set to the first option in the dictionary.

We then create an OptionMenu called option_menu that displays the list of options, using the selected_option variable to keep track of the current selection. We pack the OptionMenu onto the main window using the pack() method.

Finally, we loop through the options dictionary using the items() method, and use the add_command() method on the OptionMenu's "menu" attribute to dynamically create each option and bind its corresponding command. This approach allows us to define a large number of options and commands in a concise and readable way.

Output

When we run this code, we see the drop-down menu of options −

And when we select an option, we see the corresponding message printed to the console −

Selected option: Option4

Conclusion

In this article, we've explored a concise way to configure the Tkinter OptionMenu widget using Python. We've covered the basic syntax of the OptionMenu widget, how to set the initial selected option, how to bind a command to the selection, and a concise way to define options and their corresponding commands using a dictionary and loop. By using these techniques, you can create intuitive and interactive GUIs in Python that allow users to select from a list of options with ease.