Set a default value for a ttk Combobox in Tkinter?

Tkinter Combobox is used to add a drop-down menu to the Entry widget, making it useful to handle multiple data in any application. A Combobox widget can be created using ttk.Combobox(). To set a default value, we specify the index of the desired value using the current(index) method.

Syntax

To set a default value for a ttk Combobox ?

combobox = ttk.Combobox(parent, values=('value1', 'value2', 'value3'))
combobox.current(index)  # index starts from 0

Example

Here's how to create a Combobox with a default value ?

# Import Tkinter library
from tkinter import *
from tkinter import ttk

# Create an instance of Tkinter frame or window
win = Tk()

# Set the geometry of tkinter frame
win.geometry("750x250")
win.title("Combobox Default Value Example")

# Create a Combobox
combobox = ttk.Combobox(win, state="readonly")
combobox['values'] = ('C++', 'Java', 'Python')

# Set default value to 'Python' (index 2)
combobox.current(2)
combobox.pack(pady=30, ipadx=20)

print("Default value set to:", combobox.get())

win.mainloop()

Default value set to: Python

Setting Default Value by String

You can also set the default value directly using the set() method ?

from tkinter import *
from tkinter import ttk

win = Tk()
win.geometry("400x200")
win.title("Set Default by String")

# Create combobox with values
languages = ['JavaScript', 'Python', 'Java', 'C#']
combobox = ttk.Combobox(win, values=languages, state="readonly")

# Set default value by string
combobox.set('Python')
combobox.pack(pady=20)

print("Selected language:", combobox.get())

win.mainloop()

Selected language: Python

Methods Comparison

Conclusion

Use current(index) to set default value by position or set(value) to set by exact string. Both methods ensure your Combobox starts with a meaningful default selection.