Common Widget Properties¶

Each widget has a set of properties that define its visual appearance on the computer screen and how it responds to user events. There is a set of properties that all tk widgets have in common. Some of these are shown in the following table.

You can treat a widget object as a dictionary and use the property names as keys to access and change the property values. For example, to change the background color and width of a widget whose object variable is named sam, you could do this:

sam = tk.Button(application_window, text="Sam's Button")
sam['bg'] = 'red'
sam['width'] = 60  # pixels

Specific Widget Properties¶

Each type of widget has properties specific to its intended use. Here are some examples:

Some widgets have a “variable” that a user manipulates. For such widgets you must create a special tk object that stores the widget’s value. Basically you are creating a non-visible widget that can have events associated with it. You can access the widget’s value through .set(new_value) and .get() methods on the variable object. There are four types of variable objects:

Let’s take a tk.Checkbutton as an example and walk through the steps needed to get and set its “value”. You need to do three things:

1. Create a tk.BooleanVar object. (Actually any type of variable object can be used.)

2. Give the tk.BooleanVar object the initial value you want for the checkbutton.

3. Assign the variable attribute of the checkbutton to the tk.BooleanVar object.

In code this looks like this:

checkbutton_value = tk.BooleanVar()
checkbutton_value.set(True)  # The checkbutton will be "checked"

my_checkbutton = tk.Checkbutton(parent_widget, text="Example check box")
my_checkbutton['variable'] = checkbutton_value

If you want the value of the checkbutton at any time while your program is running, you get the value of the variable object like this:

the_current_value_of_the_checkbutton = checkbutton_value.get()

And you can change the state of the checkbutton at any time using a call to .set() like this:

checkbutton_value.set(FALSE)  # set the checkbutton to "un-checked"

Widget Attributes¶

The following web pages provide a good description of the properties that can be modified for individual widgets: