How to Create Dropdown in Tkinter in Python Easily

To create a dropdown in Tkinter, use the OptionMenu widget by passing a parent widget, a StringVar variable, and a list of options. This widget displays a clickable menu where users can select one option from the list.

Syntax

The basic syntax to create a dropdown menu in Tkinter is:

• variable = tk.StringVar(): Holds the selected option.
• OptionMenu(parent, variable, *options): Creates the dropdown widget.
• variable.set(default_option): Sets the initially selected option.

python

variable = tk.StringVar()
dropdown = tk.OptionMenu(parent, variable, option1, option2, option3)
variable.set(option1)  # default value

Example

This example shows a simple Tkinter window with a dropdown menu to select a fruit. The selected fruit is printed when changed.

python

import tkinter as tk

def on_select(value):
    print(f"Selected: {value}")

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

options = ["Apple", "Banana", "Cherry", "Date"]
selected_option = tk.StringVar(root)
selected_option.set(options[0])  # default value

dropdown = tk.OptionMenu(root, selected_option, *options)
dropdown.config(command=on_select)
dropdown.pack(padx=20, pady=20)

root.mainloop()

Output

When user selects an option, e.g., 'Banana', console prints: Selected: Banana

Common Pitfalls

Common mistakes when creating dropdowns in Tkinter include:

• Not using a StringVar to track the selected value, so you can't get the user's choice.
• Forgetting to set a default value with variable.set(), which can cause the dropdown to appear empty initially.
• Passing options incorrectly (must be separate arguments, not a list without unpacking).

python

import tkinter as tk

root = tk.Tk()

options = ["Red", "Green", "Blue"]

# Wrong: passing list directly without unpacking
# dropdown = tk.OptionMenu(root, tk.StringVar(), options)  # This will not work

# Right way:
selected = tk.StringVar(root)
selected.set(options[0])
dropdown = tk.OptionMenu(root, selected, *options)
dropdown.pack()

root.mainloop()

Quick Reference

Summary tips for creating dropdowns in Tkinter:

• Use tk.StringVar() to hold the selected option.
• Pass options as separate arguments using *options.
• Set a default option with variable.set().
• Use the command parameter to handle selection changes.

Key Takeaways

Use Tkinter's OptionMenu widget with a StringVar to create dropdowns.

Always set a default value with variable.set() to avoid empty dropdowns.

Pass options as separate arguments using the * operator, not as a list.

Use the command parameter to run code when the user selects an option.