Tkinter OptionMenu
Summary: in this tutorial, you’ll learn about the Tkinter OptionMenu
widget to display a set of options in a drop-down menu.
Introduction to the Tkinter OptionMenu
widget
The OptionMenu
widget provides you with a predefined set of options in a drop-down menu.
To create a new OptionMenu
widget, you use the OptionMenu
constructor:
OptionMenu(container, variable, default=None, *values, **kwargs)
Code language: Python (python)
The OptionMenu
constructor accepts a number of parameters:
container
is the parent widget of theOptionMenu
widget.variable
is atk.StringVar
object that holds the currently selected option of theOptionMenu
.default
is the default option that the widget displays initially.values
is a list of values that appear on the drop-down menu.kwargs
is the widget-specific configuration.
The OptionMenu
allows you to change the direction of the drop-down menu via the direction
option. The valid directions are 'above'
, 'below'
, 'left'
, 'right'
, or 'flush'
.
The OptionMenu
widget also supports the command
option. This allows you to assign a callback that will be called after an item is selected.
Like other ttk widgets, you can specify the style name for the OptionMenu
using the style
option.
Tkinter OptionMenu
widget example
The following example illustrates how to use an OptionMenu
widget. When you select an item, it’ll show your selection in a label:
import tkinter as tk
from tkinter import ttkclass App(tk.Tk):
def __init__(self):
super().__init__()
self.geometry("320x80")
self.title('Tkinter OptionMenu Widget')
# initialize data
self.languages = ('Python', 'JavaScript', 'Java',
'Swift', 'GoLang', 'C#', 'C++', 'Scala')
# set up variable
self.option_var = tk.StringVar(self)
# create widget
self.create_wigets()
def create_wigets(self):
# padding for widgets using the grid layout
paddings = {'padx': 5, 'pady': 5}
# label
label = ttk.Label(self, text='Select your most favorite language:')
label.grid(column=0, row=0, sticky=tk.W, **paddings)
# option menu
option_menu = ttk.OptionMenu(
self,
self.option_var,
self.languages[0],
*self.languages,
command=self.option_changed)
option_menu.grid(column=1, row=0, sticky=tk.W, **paddings)
# output label
self.output_label = ttk.Label(self, foreground='red')
self.output_label.grid(column=0, row=1, sticky=tk.W, **paddings)
def option_changed(self, *args):
self.output_label['text'] = f'You selected: {self.option_var.get()}'
if __name__ == "__main__":
app = App()
app.mainloop()
Code language: Python (python)
Output:
How it works.
First, define a list of strings used for displaying on the OptionMenu
widget:
self.languages = ('Python', 'JavaScript', 'Java', 'Swift', 'GoLang', 'C#', 'C++', 'Scala')
Code language: Python (python)
Second, define a ttk.StringVar()
object that holds the currently selected item of the OptionMenu
in the __init__()
method:
self.option_var = tk.StringVar(self)
Code language: Python (python)
Third, create a new instance of the OptionMenu
widget:
option_menu = ttk.OptionMenu(
self,
self.option_var,
self.languages[0],
*self.languages,
command=self.option_changed)
Code language: Python (python)
Note that if you skip the default value self.languages[0]
, the first item of the OptionMenu
will vanish.
The option_changed()
method will be executed after an item is selected. The method sets the text for the output_label
to the selected item:
self.output_label['text'] = f'You selected: {self.option_var.get()}'
Code language: PHP (php)
Summary
- Use Tkinter
OptionMenu
widget to provide users with a fixed set of choices in a drop-down menu. - Always specify the default value for the
OptionMenu
constructor.