{"id":7341,"date":"2025-04-01T08:04:52","date_gmt":"2025-04-01T08:04:52","guid":{"rendered":"https:\/\/www.pythontutorial.net\/?page_id=7341"},"modified":"2025-04-01T08:05:18","modified_gmt":"2025-04-01T08:05:18","slug":"tkinter-booleanvar","status":"publish","type":"page","link":"https:\/\/www.pythontutorial.net\/tkinter\/tkinter-booleanvar\/","title":{"rendered":"Tkinter BooleanVar"},"content":{"rendered":"\n<p><strong>Summary:<\/strong>&nbsp;In this tutorial, you&#8217;ll learn how to use the Tkinter&nbsp;<code>BooleanVar<\/code>&nbsp;class to track the boolean state of a widget.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id='introduction-to-tkinter-booleanvar'>Introduction to Tkinter BooleanVar <a href=\"#introduction-to-tkinter-booleanvar\" class=\"anchor\" id=\"introduction-to-tkinter-booleanvar\" title=\"Anchor for Introduction to Tkinter BooleanVar\">#<\/a><\/h2>\n\n\n\n<p>In Tkinter, the&nbsp;<code>BooleanVar<\/code>&nbsp;class is a subclass of the&nbsp;<code>Variable<\/code>&nbsp;class. It is a variable class that holds a boolean value.<\/p>\n\n\n\n<p>Like\u00a0<code><a href=\"https:\/\/www.pythontutorial.net\/tkinter\/tkinter-stringvar\/\">StringVar<\/a><\/code>,\u00a0<code><a href=\"https:\/\/www.pythontutorial.net\/tkinter\/tkinter-intvar\/\">IntVar<\/a><\/code>, and\u00a0<code><a href=\"https:\/\/www.pythontutorial.net\/tkinter\/tkinter-doublevar\/\">DoubleVar<\/a><\/code>, you can use the\u00a0<code>BooleanVar<\/code>\u00a0object to track the <strong>boolean state<\/strong> of a widget such as a\u00a0<code>RadioButton<\/code>\u00a0or\u00a0<code>CheckButton<\/code>.<\/p>\n\n\n\n<p>When you link a\u00a0<code>BooleanVar<\/code>\u00a0object with a widget, you can easily track and change widget values from your Python code.<\/p>\n\n\n\n<p>Linking means establishing a <strong>two-way binding<\/strong> between a\u00a0<code>BooleanVar<\/code>\u00a0object and the widget&#8217;s state. This results in automatic value synchronization between the two.<\/p>\n\n\n\n<p>In Tkinter, you can link a&nbsp;<code>BooleanVar<\/code>&nbsp;object with the following widgets:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>CheckButton<\/li>\n\n\n\n<li><a href=\"https:\/\/www.pythontutorial.net\/tkinter\/tkinter-radio-button\/\">RadioButton<\/a><\/li>\n\n\n\n<li>Menu CheckButton<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"creating-a-booleanvar-object\" id='creating-a-booleanvar-object'>Creating a BooleanVar object <a href=\"#creating-a-booleanvar-object\" class=\"anchor\" id=\"creating-a-booleanvar-object\" title=\"Anchor for Creating a BooleanVar object\">#<\/a><\/h2>\n\n\n\n<p>To create a&nbsp;<code>BooleanVar<\/code>&nbsp;object, you follow these steps:<\/p>\n\n\n\n<p>First, import Tkinter:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-1\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><span><code class=\"hljs language-javascript\"><span class=\"hljs-keyword\">import<\/span> tkinter <span class=\"hljs-keyword\">as<\/span> tk<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-1\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Second, create an instance of the&nbsp;<code>BooleanVar<\/code>&nbsp;class:<\/p>\n\n\n<pre class=\"wp-block-code\"><span><code class=\"hljs\">boolean_var = tk.BooleanVar()<\/code><\/span><\/pre>\n\n\n<p>A&nbsp;<code>BooleanVar<\/code>&nbsp;object defaults to&nbsp;<code>False<\/code>. If you want to set its value to&nbsp;<code>True<\/code>, you can use the following:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-2\" data-shcb-language-name=\"PHP\" data-shcb-language-slug=\"php\"><span><code class=\"hljs language-php\">boolean_var = tk.BooleanVar(value=<span class=\"hljs-keyword\">True<\/span>)<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-2\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PHP<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">php<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p class=\"note\">Note that you have to use the\u00a0<code>value<\/code>\u00a0keyword argument because the first parameter of the\u00a0<code>BooleanVar<\/code>\u00a0constructor is a <code>master<\/code> widget.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"associating-a-booleanvar-object-with-a-widget\" id='linking-a-booleanvar-object-with-a-widget'>Linking a BooleanVar object with a widget <a href=\"#linking-a-booleanvar-object-with-a-widget\" class=\"anchor\" id=\"linking-a-booleanvar-object-with-a-widget\" title=\"Anchor for Linking a BooleanVar object with a widget\">#<\/a><\/h2>\n\n\n\n<p>Once having a\u00a0<code>BooleanVar<\/code>\u00a0object, you can link it with a widget. For example, you can link a\u00a0<code>BooleanVar<\/code>\u00a0object with a\u00a0<code>CheckButton<\/code>\u00a0as follows:<\/p>\n\n\n<pre class=\"wp-block-code\"><span><code class=\"hljs\">check_button = ttk.Checkbutton(variable=boolean_var)<\/code><\/span><\/pre>\n\n\n<p class=\"note\">Note that you can link one BooleanVar object with one or more widgets.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"manipulating-widgets-values\" id='manipulating-widgets-values'>Manipulating widget&#8217;s values <a href=\"#manipulating-widgets-values\" class=\"anchor\" id=\"manipulating-widgets-values\" title=\"Anchor for Manipulating widget&#039;s values\">#<\/a><\/h2>\n\n\n\n<p>After linking a\u00a0<code>BooleanVar<\/code>\u00a0object with a widget, you can track and change the widget&#8217;s value via the\u00a0<code>BooleanVar<\/code>\u00a0object.<\/p>\n\n\n\n<p>For example, you can access the current value of the&nbsp;<code>CheckButton<\/code>&nbsp;using the&nbsp;<code>get()<\/code>&nbsp;method of the&nbsp;<code>BooleanVar<\/code>&nbsp;object:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-3\" data-shcb-language-name=\"CSS\" data-shcb-language-slug=\"css\"><span><code class=\"hljs language-css\"><span class=\"hljs-selector-tag\">boolean_var<\/span><span class=\"hljs-selector-class\">.get<\/span>()<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-3\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">CSS<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">css<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>You can also check the&nbsp;<code>CheckButton<\/code>&nbsp;by setting the value of the&nbsp;<code>BooleanVar<\/code>&nbsp;object to&nbsp;<code>True<\/code>:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-4\" data-shcb-language-name=\"CSS\" data-shcb-language-slug=\"css\"><span><code class=\"hljs language-css\"><span class=\"hljs-selector-tag\">boolean_var<\/span><span class=\"hljs-selector-class\">.set<\/span>(<span class=\"hljs-selector-tag\">True<\/span>)<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-4\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">CSS<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">css<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<h2 class=\"wp-block-heading\" id=\"tkinter-booleanvar-example\" id='tkinter-booleanvar-example'>Tkinter BooleanVar example <a href=\"#tkinter-booleanvar-example\" class=\"anchor\" id=\"tkinter-booleanvar-example\" title=\"Anchor for Tkinter BooleanVar example\">#<\/a><\/h2>\n\n\n\n<p>The following program illustrates how to use a&nbsp;<code>BooleanVar<\/code>&nbsp;to manage the state of a&nbsp;<code>CheckButton<\/code>&nbsp;widget:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-5\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><span><code class=\"hljs language-javascript\"><span class=\"hljs-keyword\">import<\/span> tkinter <span class=\"hljs-keyword\">as<\/span> tk\n<span class=\"hljs-keyword\">from<\/span> tkinter <span class=\"hljs-keyword\">import<\/span> ttk\n<span class=\"hljs-keyword\">from<\/span> tkinter.messagebox <span class=\"hljs-keyword\">import<\/span> showinfo\n\n\nroot = tk.Tk()\nroot.title(<span class=\"hljs-string\">\"BooleanVar Example\"<\/span>)\nroot.geometry(<span class=\"hljs-string\">\"300x80\"<\/span>)\n\ncheck_var = tk.BooleanVar(value=True)\n\ncheck_button = ttk.Checkbutton(\n    root, \n    text=<span class=\"hljs-string\">\"Check me\"<\/span>, \n    variable=check_var, \n    command=lambda: showinfo(\n        title=<span class=\"hljs-string\">\"Checkbutton State\"<\/span>, \n        message= <span class=\"hljs-string\">\"Checked\"<\/span> <span class=\"hljs-keyword\">if<\/span> check_var.get() <span class=\"hljs-keyword\">else<\/span> <span class=\"hljs-string\">\"Unchecked\"<\/span>\n    )\n)\ncheck_button.pack()\n\nroot.mainloop()<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-5\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"464\" height=\"211\" src=\"https:\/\/www.pythontutorial.net\/wp-content\/uploads\/2025\/04\/Tkinter-BooleanVar.gif\" alt=\"Tkinter BooleanVar\" class=\"wp-image-7345\"\/><\/figure>\n\n\n\n<p>How the program works<\/p>\n\n\n\n<p>First, create a&nbsp;<code>BooleanVar<\/code>&nbsp;with the default value&nbsp;<code>True<\/code>:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-6\" data-shcb-language-name=\"PHP\" data-shcb-language-slug=\"php\"><span><code class=\"hljs language-php\">check_var = tk.BooleanVar(value=<span class=\"hljs-keyword\">True<\/span>)<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-6\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PHP<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">php<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Second, create a&nbsp;<code>CheckButton<\/code>&nbsp;widget and link it with the&nbsp;<code>check_var<\/code>&nbsp;button:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-7\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><span><code class=\"hljs language-javascript\">check_button = ttk.Checkbutton(\n     root,\n     text=<span class=\"hljs-string\">\"Check me\"<\/span>,\n     variable=check_var,\n     command=lambda: showinfo(\n          title=<span class=\"hljs-string\">\"Checkbutton State\"<\/span>,\n          message=<span class=\"hljs-string\">\"Checked\"<\/span> <span class=\"hljs-keyword\">if<\/span> check_var.get() <span class=\"hljs-keyword\">else<\/span> <span class=\"hljs-string\">\"Unchecked\"<\/span>\n     )\n)<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-7\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>If you check or uncheck, the\u00a0<code>CheckButton<\/code>\u00a0will execute a <a href=\"https:\/\/www.pythontutorial.net\/python-basics\/python-lambda-expressions\/\">lambda<\/a> to show the current value retrieved from the\u00a0<code>check_var<\/code>\u00a0variable.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"summary\" id='summary'>Summary <a href=\"#summary\" class=\"anchor\" id=\"summary\" title=\"Anchor for Summary\">#<\/a><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Use a\u00a0<code>BooleanVar<\/code>\u00a0object to track and control the boolean state of a widget.<\/li>\n<\/ul>\n<div class=\"helpful-block-content\" data-title=\"\">\n\t<header>\n\t\t<div class=\"wth-question\">Was this tutorial helpful ?<\/div>\n\t\t<div class=\"wth-thumbs\">\n\t\t\t<button\n\t\t\t\tdata-post=\"7341\"\n\t\t\t\tdata-post-url=\"https:\/\/www.pythontutorial.net\/tkinter\/tkinter-booleanvar\/\"\n\t\t\t\tdata-post-title=\"Tkinter BooleanVar\"\n\t\t\t\tdata-response=\"1\"\n\t\t\t\tclass=\"wth-btn-rounded wth-yes-btn\"\n\t\t\t>\n\t\t\t\t<svg\n\t\t\t\t\txmlns=\"http:\/\/www.w3.org\/2000\/svg\"\n\t\t\t\t\tviewBox=\"0 0 24 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Tkinter\u00a0BooleanVar\u00a0class to track the boolean state of a widget.<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":1232,"menu_order":51,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-7341","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.pythontutorial.net\/wp-json\/wp\/v2\/pages\/7341","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.pythontutorial.net\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.pythontutorial.net\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.pythontutorial.net\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.pythontutorial.net\/wp-json\/wp\/v2\/comments?post=7341"}],"version-history":[{"count":5,"href":"https:\/\/www.pythontutorial.net\/wp-json\/wp\/v2\/pages\/7341\/revisions"}],"predecessor-version":[{"id":7347,"href":"https:\/\/www.pythontutorial.net\/wp-json\/wp\/v2\/pages\/7341\/revisions\/7347"}],"up":[{"embeddable":true,"href":"https:\/\/www.pythontutorial.net\/wp-json\/wp\/v2\/pages\/1232"}],"wp:attachment":[{"href":"https:\/\/www.pythontutorial.net\/wp-json\/wp\/v2\/media?parent=7341"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}