{"id":3285,"date":"2021-12-06T10:19:57","date_gmt":"2021-12-06T10:19:57","guid":{"rendered":"https:\/\/www.pythontutorial.net\/?page_id=3285"},"modified":"2021-12-10T02:00:41","modified_gmt":"2021-12-10T02:00:41","slug":"python-regex-search","status":"publish","type":"page","link":"https:\/\/www.pythontutorial.net\/python-regex\/python-regex-search\/","title":{"rendered":"Python Regex search()"},"content":{"rendered":"\n<p><strong>Summary<\/strong>: in this tutorial, you&#8217;ll learn how to use the Python regex <code>search()<\/code> function to return the first match of a pattern in a string.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id='introduction-to-the-python-regex-search-function'>Introduction to the Python regex search() function <a href=\"#introduction-to-the-python-regex-search-function\" class=\"anchor\" id=\"introduction-to-the-python-regex-search-function\" title=\"Anchor for Introduction to the Python regex search() function\">#<\/a><\/h2>\n\n\n\n<p>The regex <code>search()<\/code> is a function in the built-in <code>re<\/code> module that deals with <a href=\"https:\/\/www.pythontutorial.net\/python-regex\/python-regular-expressions\/\">regular expressions<\/a>. The <code>search()<\/code> function has the following syntax:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-1\" data-shcb-language-name=\"Python\" data-shcb-language-slug=\"python\"><span><code class=\"hljs language-python\">re.search(pattern, string, flags=<span class=\"hljs-number\">0<\/span>)<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-1\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">Python<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">python<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>In this syntax:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>pattern is a regular expression that you want to search for in the string.<\/li><li>string is the input string. <\/li><li><code>flags<\/code> is one or more <a href=\"https:\/\/www.pythontutorial.net\/python-regex\/python-regex-flags\/\">regular expression flags<\/a> that modify the standard behavior of the pattern.<\/li><\/ul>\n\n\n\n<p>The <code>search()<\/code> function scans the <code>string<\/code> from left to right and finds the first location where the <code>pattern<\/code> produces a match. It returns a <code>Match<\/code> object if the search was successful or <code>None<\/code> otherwise.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id='python-regex-search-function-examples'>Python regex search() function examples <a href=\"#python-regex-search-function-examples\" class=\"anchor\" id=\"python-regex-search-function-examples\" title=\"Anchor for Python regex search() function examples\">#<\/a><\/h2>\n\n\n\n<p>Let&#8217;s take some examples of using the <code>search()<\/code> function.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id='1-using-the-python-regex-search-fuction-to-find-the-first-match'>1) Using the Python regex search() fuction to find the first match <a href=\"#1-using-the-python-regex-search-fuction-to-find-the-first-match\" class=\"anchor\" id=\"1-using-the-python-regex-search-fuction-to-find-the-first-match\" title=\"Anchor for 1) Using the Python regex search() fuction to find the first match\">#<\/a><\/h3>\n\n\n\n<p>The following example uses the <code>search()<\/code> function to find the first number in the string:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-2\" data-shcb-language-name=\"Python\" data-shcb-language-slug=\"python\"><span><code class=\"hljs language-python\"><span class=\"hljs-keyword\">import<\/span> re\n\ns = <span class=\"hljs-string\">'Python 3 was released on Dec 3, 2008'<\/span>\npattern = <span class=\"hljs-string\">'\\d+'<\/span>\n\nmatch = re.search(pattern, s)\n\n<span class=\"hljs-keyword\">if<\/span> match <span class=\"hljs-keyword\">is<\/span> <span class=\"hljs-keyword\">not<\/span> <span class=\"hljs-literal\">None<\/span>:\n    print(match.group())\n<span class=\"hljs-keyword\">else<\/span>:\n    print(<span class=\"hljs-string\">'No match found'<\/span>)<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-2\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">Python<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">python<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Output:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-3\" data-shcb-language-name=\"Python\" data-shcb-language-slug=\"python\"><span><code class=\"hljs language-python\">&lt;re.Match object; span=(<span class=\"hljs-number\">7<\/span>, <span class=\"hljs-number\">8<\/span>), match=<span class=\"hljs-string\">'3'<\/span>&gt;<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-3\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">Python<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">python<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>In this example, the pattern <code>\\d+<\/code> matches one or more digits. The <code>search()<\/code> returns a <code>Match<\/code> object.<\/p>\n\n\n\n<p>To get the match, you can call the <code>group()<\/code> method of the <code>Match<\/code> object like this:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-4\" data-shcb-language-name=\"Python\" data-shcb-language-slug=\"python\"><span><code class=\"hljs language-python\"><span class=\"hljs-keyword\">import<\/span> re\n\ns = <span class=\"hljs-string\">'Python 3 was released on Dec 3, 2008'<\/span>\npattern = <span class=\"hljs-string\">'\\d+'<\/span>\n\n\nmatch = re.search(pattern, s)\n\n<span class=\"hljs-keyword\">if<\/span> match <span class=\"hljs-keyword\">is<\/span> <span class=\"hljs-keyword\">not<\/span> <span class=\"hljs-literal\">None<\/span>:\n    print(match.group())<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-4\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">Python<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">python<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Output:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-5\" data-shcb-language-name=\"Python\" data-shcb-language-slug=\"python\"><span><code class=\"hljs language-python\"><span class=\"hljs-number\">3<\/span><\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-5\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">Python<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">python<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<h3 class=\"wp-block-heading\" id='2-using-the-python-regex-search-function-to-find-the-first-word-that-matches-a-pattern'>2) Using the Python regex search() function to find the first word that matches a pattern  <a href=\"#2-using-the-python-regex-search-function-to-find-the-first-word-that-matches-a-pattern\" class=\"anchor\" id=\"2-using-the-python-regex-search-function-to-find-the-first-word-that-matches-a-pattern\" title=\"Anchor for 2) Using the Python regex search() function to find the first word that matches a pattern \">#<\/a><\/h3>\n\n\n\n<p>The following example uses the <code>search()<\/code> function to search the first word that ends with the literal string <code>thon<\/code> in a string:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-6\" data-shcb-language-name=\"Python\" data-shcb-language-slug=\"python\"><span><code class=\"hljs language-python\"><span class=\"hljs-keyword\">import<\/span> re\n\ns = <span class=\"hljs-string\">'CPython, IronPython, or Cython'<\/span>\npattern = <span class=\"hljs-string\">r'\\b((\\w+)thon)\\b'<\/span>\n\nmatch = re.search(pattern, s)\n\n<span class=\"hljs-keyword\">if<\/span> match <span class=\"hljs-keyword\">is<\/span> <span class=\"hljs-keyword\">not<\/span> <span class=\"hljs-literal\">None<\/span>:\n    print(match.groups())<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-6\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">Python<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">python<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Output:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-7\" data-shcb-language-name=\"Python\" data-shcb-language-slug=\"python\"><span><code class=\"hljs language-python\">(<span class=\"hljs-string\">'CPython'<\/span>, <span class=\"hljs-string\">'CPy'<\/span>)<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-7\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">Python<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">python<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>The pattern <code>r'\\b((\\w+)thon)\\b'<\/code> has two capturing groups:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><code>(\\w+)<\/code> &#8211; captures the characters at the beginning of the word.<\/li><li><code>((\\w+)thon)<\/code> &#8211; captures the whole word.<\/li><\/ul>\n\n\n\n<p>The <code>search()<\/code> function returns the first location where it finds the match. To access all the groups in a match, you use the <code>groups()<\/code> method of the match object.<\/p>\n\n\n\n<p>As clearly shown in the output, the <code>groups()<\/code> method returns a tuple that contains all the groups.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id='3-using-the-python-regex-search-function-with-a-regex-flag'>3) Using the Python regex search() function with a regex flag <a href=\"#3-using-the-python-regex-search-function-with-a-regex-flag\" class=\"anchor\" id=\"3-using-the-python-regex-search-function-with-a-regex-flag\" title=\"Anchor for 3) Using the Python regex search() function with a regex flag\">#<\/a><\/h3>\n\n\n\n<p>The following example uses the <code>search()<\/code> function to find the first <code>python<\/code> word in a string:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-8\" data-shcb-language-name=\"Python\" data-shcb-language-slug=\"python\"><span><code class=\"hljs language-python\"><span class=\"hljs-keyword\">import<\/span> re\n\ns = <span class=\"hljs-string\">'Python or python'<\/span>\npattern = <span class=\"hljs-string\">r'\\bpython\\b'<\/span>\n\nmatch = re.search(pattern, s)\nprint(match)<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-8\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">Python<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">python<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>It returns the word <code>python<\/code> with the letter <code>p<\/code> in lowercase as specified in the pattern.<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-9\" data-shcb-language-name=\"Python\" data-shcb-language-slug=\"python\"><span><code class=\"hljs language-python\">&lt;re.Match object; span=(<span class=\"hljs-number\">10<\/span>, <span class=\"hljs-number\">16<\/span>), match=<span class=\"hljs-string\">'python'<\/span>&gt;<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-9\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">Python<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">python<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>To match the word case-insensitively, you can pass the <code>re.IGNORECASE<\/code> flag to the third argument of the <code>search()<\/code> function. For example:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-10\" data-shcb-language-name=\"Python\" data-shcb-language-slug=\"python\"><span><code class=\"hljs language-python\"><span class=\"hljs-keyword\">import<\/span> re\n\ns = <span class=\"hljs-string\">'Python or python'<\/span>\npattern = <span class=\"hljs-string\">r'\\bpython\\b'<\/span>\n\nmatch = re.search(pattern, s, re.IGNORECASE)\nprint(match)<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-10\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">Python<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">python<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>In this example, the <code>search()<\/code> function returns the word <code>Python<\/code> with the letter <code>P<\/code> in uppercase:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-11\" data-shcb-language-name=\"Python\" data-shcb-language-slug=\"python\"><span><code class=\"hljs language-python\">&lt;re.Match object; span=(<span class=\"hljs-number\">0<\/span>, <span class=\"hljs-number\">6<\/span>), match=<span class=\"hljs-string\">'Python'<\/span>&gt;<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-11\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">Python<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">python<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<h2 class=\"wp-block-heading\" 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\"><li>Use the regex <code>search()<\/code> function to return the first match of a pattern in a string or <code>None<\/code> if the search was unsuccessful.<\/li><\/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=\"3285\"\n\t\t\t\tdata-post-url=\"https:\/\/www.pythontutorial.net\/python-regex\/python-regex-search\/\"\n\t\t\t\tdata-post-title=\"Python Regex search()\"\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 24\"\n\t\t\t\t\tfill=\"none\"\n\t\t\t\t\tstroke=\"currentColor\"\n\t\t\t\t\tstroke-width=\"2\"\n\t\t\t\t\tstroke-linecap=\"round\"\n\t\t\t\t\tstroke-linejoin=\"round\"\n\t\t\t\t\tclass=\"feather feather-thumbs-up block w-full h-full\"\n\t\t\t\t>\n\t\t\t\t\t<path\n\t\t\t\t\t\td=\"M14 9V5a3 3 0 0 0-3-3l-4 9v11h11.28a2 2 0 0 0 2-1.7l1.38-9a2 2 0 0 0-2-2.3zM7 22H4a2 2 0 0 1-2-2v-7a2 2 0 0 1 2-2h3\"\n\t\t\t\t\t><\/path>\n\t\t\t\t<\/svg>\n\t\t\t\t<span class=\"sr-only\"> Yes <\/span>\n\t\t\t<\/button>\n\n\t\t\t<button\n\t\t\t\tdata-response=\"0\"\n\t\t\t\tdata-post=\"3285\"\n\t\t\t\tdata-post-url=\"https:\/\/www.pythontutorial.net\/python-regex\/python-regex-search\/\"\n\t\t\t\tdata-post-title=\"Python Regex search()\"\n\t\t\t\tclass=\"wth-btn-rounded wth-no-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 24\"\n\t\t\t\t\tfill=\"none\"\n\t\t\t\t\tstroke=\"currentColor\"\n\t\t\t\t\tstroke-width=\"2\"\n\t\t\t\t\tstroke-linecap=\"round\"\n\t\t\t\t\tstroke-linejoin=\"round\"\n\t\t\t\t>\n\t\t\t\t\t<path\n\t\t\t\t\t\td=\"M10 15v4a3 3 0 0 0 3 3l4-9V2H5.72a2 2 0 0 0-2 1.7l-1.38 9a2 2 0 0 0 2 2.3zm7-13h2.67A2.31 2.31 0 0 1 22 4v7a2.31 2.31 0 0 1-2.33 2H17\"\n\t\t\t\t\t><\/path>\n\t\t\t\t<\/svg>\n\t\t\t\t<span class=\"sr-only\"> No <\/span>\n\t\t\t<\/button>\n\t\t<\/div>\n\t<\/header>\n\n\t<div class=\"wth-form hidden\">\n\t\t<div class=\"wth-form-wrapper\">\n\t\t\t<div class=\"wth-title\"><\/div>\n\t\t\t<textarea class=\"wth-message\"><\/textarea>\n\t\t\t<input type=\"button\" name=\"wth-submit\" class=\"wth-btn wth-btn-submit\" id=\"wth-submit\" \/>\n\t\t\t<input type=\"button\" class=\"wth-btn wth-btn-cancel\" value=\"Cancel\" \/>\n\t\t<\/div>\n\t<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>In this tutorial, you&#8217;ll learn how to use the Python regex search() function to the first match of a pattern in a string.<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":3122,"menu_order":18,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-3285","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.pythontutorial.net\/wp-json\/wp\/v2\/pages\/3285","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=3285"}],"version-history":[{"count":0,"href":"https:\/\/www.pythontutorial.net\/wp-json\/wp\/v2\/pages\/3285\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/www.pythontutorial.net\/wp-json\/wp\/v2\/pages\/3122"}],"wp:attachment":[{"href":"https:\/\/www.pythontutorial.net\/wp-json\/wp\/v2\/media?parent=3285"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}