Configuration#

Every widget’s appearance and behavior are held in named options, set at construction and changed afterward with these methods. Each widget page lists the options that widget accepts; the methods here are how you read and write them.

configure(cnf=None, **options)

Set one or more options after construction. Alias: config. The item syntax widget["option"] = value is equivalent to a one-option configure.

Parameters:

  • options – option/value pairs to set.

  • cnf – an optional dict of options (merged with options).

Returns:

with no arguments, a dict mapping every option name to its spec (name, dbName, dbClass, default, current); with a single option name and no value, that one option’s spec; otherwise None.

Raises:

TclError – if an option is not one the widget accepts.

cget(key)

Return the current value of one option. Equivalent to widget["option"].

Parameters:

key (str) – the option name.

Returns:

the option’s current value, as Tk holds it. The Python type follows the option — str for text, int for width (even if set from a string), tuple for padding. Options given an object, such as command or textvariable, come back as the name Tk registered, not the callable or variable you passed.

Raises:

TclError – if key is not an option the widget accepts.

keys()

List the names of the options this widget accepts.

Returns:

the option names.

Return type:

list[str]

A value read back is Tk’s, so its type is Tk’s too. To convert one — especially a Tk boolean, where "no" and "0" are truthy strings to Python — use getboolean/getint/getdouble from Interpreter.

The option database#

Tk has a second, older way to set option values: an option database of patterns matched against widget names and classes, which supplies a default for any option a widget wasn’t given explicitly. The methods are option_add, option_get, option_clear and option_readfile.

It is standard Tk, not ttk, so it does not reach a ttk widget at all — a ttk Button has no background option to default; appearance there comes from the theme and bootstyle. It applies only to the classic tk widgets (Text, Canvas, Listbox, Menu) — and even there ttkbootstrap paints them with the active theme when they are created, which overrides the database. To let it through, opt that widget out of theming:

app.option_add("*Text.background", "#fdf6e3")

ttk.Text(app)                    # '#ffffff'  -- the theme wins
ttk.Text(app, autostyle=False)   # '#fdf6e3'  -- the database wins

So it is rarely the right tool here: setting the option on the widget is clearer, and theming already covers the job it was invented for. It is documented because the tk widgets make it reachable, and you will meet it in older tkinter code. The Tk option manual has the pattern syntax and precedence rules.

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