{"id":298,"date":"2022-01-17T00:00:00","date_gmt":"2022-01-17T00:00:00","guid":{"rendered":"https:\/\/tac.debuzzify.com\/?p=298"},"modified":"2023-06-21T13:29:13","modified_gmt":"2023-06-21T13:29:13","slug":"python-get-element-index","status":"publish","type":"post","link":"https:\/\/www.the-analytics.club\/python-get-element-index\/","title":{"rendered":"How to Find the Index of an Element in a List in Python?"},"content":{"rendered":"\n\n\n<p>We can get the index of an element in a Python list using the `index` method available on lists. Call this method by specifying what to search. If it is available, we get its index; otherwise, we get a value error. We can also set when to start and stop searching while searching for an element.<\/p>\n\n\n\n<p>Here&#8217;s how to search for indexes of elements in a list.<\/p>\n\n\n\n<p><script><br \/>\n            \/* This is ugly, but to ensure we only create this function once, and only call<br \/>\n            each JS library once, we need to check here in case there are multiple Wagtail<br \/>\n            blocks on this page. This will ensure we only load the minimum payload. *\/<br \/>\n            if(typeof loadPrismLanguage != 'function') {<br \/>\n                window.loadPrismLanguage = function(language) {<br \/>\n                    var libraries = [<br \/>\n                        {<br \/>\n                            \"id\": \"code-block-prismjs\",<br \/>\n                            \"url\": \"\/\/cdnjs.cloudflare.com\/ajax\/libs\/prism\/1.25.0\/prism.min.js\"<br \/>\n                        },<br \/>\n                        {<br \/>\n                            \"id\": \"code-block-prismjs-\" + language,<br \/>\n                            \"url\": \"\/\/cdnjs.cloudflare.com\/ajax\/libs\/prism\/1.25.0\/components\/prism-\" + language + \".min.js\"<br \/>\n                        },<br \/>\n        {<br \/>\n            \"id\": \"code-block-line-numbers\",<br \/>\n            \"url\": \"\/\/cdnjs.cloudflare.com\/ajax\/libs\/prism\/1.25.0\/plugins\/line-numbers\/prism-line-numbers.min.js\"<br \/>\n        }<\/p>\n<p>                    ];<\/p>\n<p>                    for(const library of libraries) {<br \/>\n                        if(document.getElementById(library[\"id\"]) == null) {<br \/>\n                            var s = document.createElement(\"script\");<br \/>\n                            s.id = library[\"id\"];<br \/>\n                            s.type = \"text\/javascript\";<br \/>\n                            s.src = library[\"url\"];<br \/>\n                            s.async = false;<br \/>\n                            document.body.appendChild(s);<br \/>\n                        }<br \/>\n                    }<br \/>\n                };<br \/>\n            }<\/p>\n<p>            loadPrismLanguage('python');<\/p>\n<p>            language_class_name = 'language-python';<br \/>\n            <\/script><\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro padding-bottom-disabled\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:16px;font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:20px\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" data-code=\"l = ['apple', 'orange', 'mango']\nl.index('orange')\n\n&gt;&gt;&gt; 1\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #D8DEE9\">l<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> [<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">apple<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">orange<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">mango<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #D8DEE9FF\">]<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9\">l<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">index<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">orange<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #D8DEE9FF\">)<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;&gt;&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><\/span><\/code><\/pre><span style=\"display:flex;align-items:flex-end;padding:10px;width:100%;justify-content:flex-end;background-color:#2e3440ff;color:#c8d0e0;font-size:12px;line-height:1;position:relative\">JavaScript<\/span><\/div>\n\n\n\n<p><script><br \/>\n                var block_num = (typeof block_num === 'undefined') ? 0 : block_num;<br \/>\n                block_num++;<br \/>\n                document.getElementById('target-element-current').className = language_class_name;<br \/>\n                document.getElementById('target-element-current').id = 'target-element-' + block_num;<br \/>\n            <\/script><\/p>\n\n\n\n<p>In the above example, the list comprises three fruits. In this list, we search the index of orange. The output shows the position of orange in the list is one.<\/p>\n\n\n\n<p>Python uses a zero-based index system. This is why the second element of the list has an index of 1.<\/p>\n\n\n\n<p>Suppose we try to get the index of grapes in this list; we&#8217;ll get a value error instead. If an element does not exist on the list, the index method will always through a value error. The error message will tell us which element was searched but was not available. This is very useful when debugging large codebases.<\/p>\n\n\n\n<p>Here&#8217;s how it works.<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro padding-bottom-disabled\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:16px;font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:20px\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" data-code=\"l.index('grapes')\nTraceback (most recent call last):\n  File &quot;<stdin&gt;&quot;, line 1, in <module&gt;\nValueError: 'grapes' is not in list\n\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #D8DEE9\">l<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">index<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">grapes<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #D8DEE9FF\">)<\/span><\/span>\n<span class=\"line\"><span style=\"color: #88C0D0\">Traceback<\/span><span style=\"color: #D8DEE9FF\"> (<\/span><span style=\"color: #D8DEE9\">most<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">recent<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">call<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">last<\/span><span style=\"color: #D8DEE9FF\">):<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #D8DEE9\">File<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">&quot;<\/span><span style=\"color: #A3BE8C\">&lt;stdin&gt;<\/span><span style=\"color: #ECEFF4\">&quot;<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">line<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">in<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">&lt;<\/span><span style=\"color: #8FBCBB\">module<\/span><span style=\"color: #81A1C1\">&gt;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">ValueError<\/span><span style=\"color: #ECEFF4\">:<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">grapes<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">is<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">not<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">in<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">list<\/span><\/span>\n<span class=\"line\"><\/span><\/code><\/pre><span style=\"display:flex;align-items:flex-end;padding:10px;width:100%;justify-content:flex-end;background-color:#2e3440ff;color:#c8d0e0;font-size:12px;line-height:1;position:relative\">JavaScript<\/span><\/div>\n\n\n\n<p>The index method is a convenient way to find the index of an element. Yet, before we use it in our scripts, we should be aware of a couple of things.<\/p>\n\n\n\n<p><em>Related: <a href=\"\/python-cli-tutorial\"><strong>How to Create Interactive CLIs in Python?<\/strong><\/a><\/em><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Searching the index of elements can be slow if the list is very long.<\/h2>\n\n\n\n<p>Large lists are very common in data-driven applications. Yet, it is not advisable to find the index of an element in such a list. It&#8217;s better to avoid such operations at all costs.<\/p>\n\n\n\n<p>Here&#8217;s an example. Suppose we have a list of one million records, and we want to find out the index of 999,999 in this list will take some significant time. This is because the index method search for elements one-by-one. It needs to go through all the 999,999 elements to find the index of the same.<\/p>\n\n\n\n<p>But wait.<\/p>\n\n\n\n<p>Index searching in Python list is of order O(n). Which means it doesn&#8217;t become slower and slower with the size of the list.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote\">\n<p>Index search in Python lists have a linear time-complexity.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">Use start and end parameters to speed up the index search.<\/h2>\n\n\n\n<p>One way to improve the search is to specify the start and end parameters. For instance, by setting the start value as 999,000 and the end value as 1,000,000, we can narrow the search to only 1000 elements.<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro padding-bottom-disabled\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:16px;font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:20px\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" data-code=\"l = list(range(1000000))\nl.index(999999,999000,1000000)\n\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #D8DEE9\">l<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">list<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #88C0D0\">range<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #B48EAD\">1000000<\/span><span style=\"color: #D8DEE9FF\">))<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9\">l<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">index<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #B48EAD\">999999<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #B48EAD\">999000<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #B48EAD\">1000000<\/span><span style=\"color: #D8DEE9FF\">)<\/span><\/span>\n<span class=\"line\"><\/span><\/code><\/pre><span style=\"display:flex;align-items:flex-end;padding:10px;width:100%;justify-content:flex-end;background-color:#2e3440ff;color:#c8d0e0;font-size:12px;line-height:1;position:relative\">JavaScript<\/span><\/div>\n\n\n\n<p>Besides speeding up, start and end parameters are also helpful for implementing search with complex logic.<\/p>\n\n\n\n<p><em>Related: <a href=\"\/python-code-formatting-git-pre-commit-hook\"><strong>Git Pre-commit Hooks for Automatic Python Code Formatting<\/strong><\/a><\/em><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">The index method only finds one (the first) element that matches the search.<\/h2>\n\n\n\n<p>Suppose there is more than one matching element in the list, and we need the indexes of both of them. The index method of the list won&#8217;t help in this situation. It&#8217;ll always return the first element&#8217;s index that matches the search.<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro padding-bottom-disabled\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:16px;font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:20px\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" data-code=\"l = ['a', 'b', 'a', 'c']\nl.index('a') # we expect 0 and 2\n\n&gt;&gt;&gt; 0\n\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #D8DEE9\">l<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> [<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">a<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">b<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">a<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">c<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #D8DEE9FF\">]<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9\">l<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">index<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">a<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #D8DEE9FF\">) # <\/span><span style=\"color: #D8DEE9\">we<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">expect<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">and<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">2<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">&gt;&gt;&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">0<\/span><\/span>\n<span class=\"line\"><\/span><\/code><\/pre><span style=\"display:flex;align-items:flex-end;padding:10px;width:100%;justify-content:flex-end;background-color:#2e3440ff;color:#c8d0e0;font-size:12px;line-height:1;position:relative\">JavaScript<\/span><\/div>\n\n\n\n<p>We can use list comprehensions to get the index of more than one match in the list. List comprehensions are one of the beautiful things about Python.<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro padding-bottom-disabled\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:16px;font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:20px\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" data-code=\"l = ['a', 'b', 'a', 'c']\n\n &gt;&gt;&gt; [0, 2] \" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #D8DEE9\">l<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> [<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">a<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">b<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">a<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">c<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #D8DEE9FF\">]<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">&gt;&gt;&gt;<\/span><span style=\"color: #D8DEE9FF\"> [<\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #D8DEE9FF\">] <\/span><\/span><\/code><\/pre><span style=\"display:flex;align-items:flex-end;padding:10px;width:100%;justify-content:flex-end;background-color:#2e3440ff;color:#c8d0e0;font-size:12px;line-height:1;position:relative\">JavaScript<\/span><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">Handle the exception when there&#8217;s no valid match.<\/h2>\n\n\n\n<p>When there&#8217;s no match, instead of returning None Python interpreter raises a Value Error. This is okay if you&#8217;re experimenting. But this will break your code in real applications. You must put excepting handling to avoid this.<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro padding-bottom-disabled\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:16px;font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:20px\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" data-code=\"l = ['apple', 'orange', 'mango']\ntry:\n  l.index('grapes')\nexcept ValueError:\n  print(&quot;This list does not contain grapes&quot;)\n\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #D8DEE9\">l<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> [<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">apple<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">orange<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">mango<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #D8DEE9FF\">]<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">try<\/span><span style=\"color: #D8DEE9FF\">:<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #D8DEE9\">l<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">index<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #A3BE8C\">grapes<\/span><span style=\"color: #ECEFF4\">&#39;<\/span><span style=\"color: #D8DEE9FF\">)<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9\">except<\/span><span style=\"color: #D8DEE9FF\"> ValueError<\/span><span style=\"color: #ECEFF4\">:<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  <\/span><span style=\"color: #88C0D0\">print<\/span><span style=\"color: #D8DEE9FF\">(<\/span><span style=\"color: #ECEFF4\">&quot;<\/span><span style=\"color: #A3BE8C\">This list does not contain grapes<\/span><span style=\"color: #ECEFF4\">&quot;<\/span><span style=\"color: #D8DEE9FF\">)<\/span><\/span>\n<span class=\"line\"><\/span><\/code><\/pre><span style=\"display:flex;align-items:flex-end;padding:10px;width:100%;justify-content:flex-end;background-color:#2e3440ff;color:#c8d0e0;font-size:12px;line-height:1;position:relative\">JavaScript<\/span><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<blockquote class=\"wp-block-quote\">\n<p>Thanks for the read, friend. It seems you and I have lots of common interests. Say Hi to me on <a href=\"https:\/\/www.linkedin.com\/in\/thuwarakesh\/\" target=\"_blank\" rel=\"nofollow noopener\">LinkedIn<\/a>, <a href=\"https:\/\/twitter.com\/Thuwarakesh\" target=\"_blank\" rel=\"nofollow noopener\">Twitter<\/a>, and <a href=\"https:\/\/thuwarakesh.medium.com\/subscribe\" target=\"_blank\" rel=\"nofollow noopener\">Medium<\/a>. I\u2019ll break the ice for you.<\/p>\n\n\n\n<p>Not a Medium member yet? Please use this link to <a href=\"https:\/\/thuwarakesh.medium.com\/membership\" target=\"_blank\" rel=\"nofollow noopener\">become a member<\/a> because I earn a commission for referring at no extra cost for you.<\/p>\n<\/blockquote>\n","protected":false},"excerpt":{"rendered":"<p>The index method of a list helps us find the location of an element in the list. But it returns only the first element, throws a ValueError when there&#8217;s no match.<\/p>\n","protected":false},"author":2,"featured_media":153,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_kad_blocks_custom_css":"","_kad_blocks_head_custom_js":"","_kad_blocks_body_custom_js":"","_kad_blocks_footer_custom_js":"","_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"footnotes":""},"categories":[3,5],"tags":[],"taxonomy_info":{"category":[{"value":3,"label":"Python"},{"value":5,"label":"Programming"}]},"featured_image_src_large":["https:\/\/www.the-analytics.club\/wp-content\/uploads\/2023\/06\/list-index-1024x695.jpg",1024,695,true],"author_info":{"display_name":"Thuwarakesh","author_link":"https:\/\/www.the-analytics.club\/author\/thuwarakesh\/"},"comment_info":0,"category_info":[{"term_id":3,"name":"Python","slug":"python","term_group":0,"term_taxonomy_id":3,"taxonomy":"category","description":"","parent":5,"count":52,"filter":"raw","cat_ID":3,"category_count":52,"category_description":"","cat_name":"Python","category_nicename":"python","category_parent":5},{"term_id":5,"name":"Programming","slug":"programming","term_group":0,"term_taxonomy_id":5,"taxonomy":"category","description":"","parent":0,"count":43,"filter":"raw","cat_ID":5,"category_count":43,"category_description":"","cat_name":"Programming","category_nicename":"programming","category_parent":0}],"tag_info":false,"_links":{"self":[{"href":"https:\/\/www.the-analytics.club\/wp-json\/wp\/v2\/posts\/298"}],"collection":[{"href":"https:\/\/www.the-analytics.club\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.the-analytics.club\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.the-analytics.club\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.the-analytics.club\/wp-json\/wp\/v2\/comments?post=298"}],"version-history":[{"count":1,"href":"https:\/\/www.the-analytics.club\/wp-json\/wp\/v2\/posts\/298\/revisions"}],"predecessor-version":[{"id":783,"href":"https:\/\/www.the-analytics.club\/wp-json\/wp\/v2\/posts\/298\/revisions\/783"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.the-analytics.club\/wp-json\/wp\/v2\/media\/153"}],"wp:attachment":[{"href":"https:\/\/www.the-analytics.club\/wp-json\/wp\/v2\/media?parent=298"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.the-analytics.club\/wp-json\/wp\/v2\/categories?post=298"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.the-analytics.club\/wp-json\/wp\/v2\/tags?post=298"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}