{
    "componentChunkName": "component---src-templates-blog-post-js",
    "path": "/creating-python-lists-using-list-comprehension/",
    "result": {"data":{"markdownRemark":{"html":"<p>We can create a list in Python simply by writing comma separated values (<em>items</em>) in square brackets.</p>\n<p><strong>Example:</strong></p>\n<pre class=\"grvsc-container synthwave-84\" data-language=\"py\" data-index=\"0\"><code class=\"grvsc-code\"><span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"1\"></span><span class=\"grvsc-source\"><span class=\"mtk15\">name </span><span class=\"mtk12\">=</span><span class=\"mtk15\"> [</span><span class=\"mtk16\">&#39;hemanta&#39;</span><span class=\"mtk15\">, </span><span class=\"mtk16\">&#39;kumar&#39;</span><span class=\"mtk15\">, </span><span class=\"mtk16\">&#39;sundaray&#39;</span><span class=\"mtk15\">]</span></span></span></code></pre>\n<p>We can also create a list using a <em>for</em> loop.</p>\n<p><strong>Example:</strong></p>\n<pre class=\"grvsc-container synthwave-84\" data-language=\"py\" data-index=\"1\"><code class=\"grvsc-code\"><span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"1\"></span><span class=\"grvsc-source\"><span class=\"mtk15\">squared </span><span class=\"mtk12\">=</span><span class=\"mtk15\"> []</span></span></span>\n<span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"2\"></span><span class=\"grvsc-source\"></span></span>\n<span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"3\"></span><span class=\"grvsc-source\"><span class=\"mtk10\">for</span><span class=\"mtk15\"> num </span><span class=\"mtk10\">in</span><span class=\"mtk15\"> </span><span class=\"mtk6\">range</span><span class=\"mtk15\">(</span><span class=\"mtk5\">5</span><span class=\"mtk15\">):</span></span></span>\n<span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"4\"></span><span class=\"grvsc-source\"><span class=\"mtk15\">    squared.</span><span class=\"mtk6\">append</span><span class=\"mtk15\">(num </span><span class=\"mtk10\">*</span><span class=\"mtk15\"> num)</span></span></span>\n<span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"5\"></span><span class=\"grvsc-source\"></span></span>\n<span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"6\"></span><span class=\"grvsc-source\"><span class=\"mtk6\">print</span><span class=\"mtk15\">(squared)</span></span></span>\n<span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"7\"></span><span class=\"grvsc-source\"><span class=\"mtk4 mtki\"># [0, 1, 4, 9, 16]</span></span></span></code></pre>\n<p>We can create the list we created in the code example above (using <em>for</em> loop) in fewer lines of code using list comprehension.</p>\n<blockquote>\n<p>We create a list comprehension with square brackets that contain an expression followed by a <em>for</em> clause followed by zero or more <em>for</em> or <em>if</em> clauses.</p>\n</blockquote>\n<p><strong>Example:</strong></p>\n<pre class=\"grvsc-container synthwave-84\" data-language=\"py\" data-index=\"2\"><code class=\"grvsc-code\"><span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"1\"></span><span class=\"grvsc-source\"><span class=\"mtk15\">squared </span><span class=\"mtk12\">=</span><span class=\"mtk15\"> [num </span><span class=\"mtk10\">*</span><span class=\"mtk15\"> num </span><span class=\"mtk10\">for</span><span class=\"mtk15\"> num </span><span class=\"mtk10\">in</span><span class=\"mtk15\"> </span><span class=\"mtk6\">range</span><span class=\"mtk15\">(</span><span class=\"mtk5\">5</span><span class=\"mtk15\">)]</span></span></span>\n<span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"2\"></span><span class=\"grvsc-source\"></span></span>\n<span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"3\"></span><span class=\"grvsc-source\"><span class=\"mtk6\">print</span><span class=\"mtk15\">(squared)</span></span></span>\n<span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"4\"></span><span class=\"grvsc-source\"><span class=\"mtk4 mtki\"># [0, 1, 4, 9, 16]</span></span></span></code></pre>\n<p><span\n      class=\"gatsby-resp-image-wrapper\"\n      style=\"position: relative; display: block; margin-left: auto; margin-right: auto; max-width: 700px; \"\n    >\n      <a\n    class=\"gatsby-resp-image-link\"\n    href=\"/static/b55a7b7b4c94ff63959b618e5ae1fa31/a27c6/listComprehension.png\"\n    style=\"display: block\"\n    target=\"_blank\"\n    rel=\"noopener\"\n  >\n    <span\n    class=\"gatsby-resp-image-background-image\"\n    style=\"padding-bottom: 43%; position: relative; bottom: 0; left: 0; background-image: url('data:image/png;base64,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'); background-size: cover; display: block;\"\n  ></span>\n  <img\n        class=\"gatsby-resp-image-image\"\n        alt=\"List Comprehension\"\n        title=\"List Comprehension\"\n        src=\"/static/b55a7b7b4c94ff63959b618e5ae1fa31/a27c6/listComprehension.png\"\n        srcset=\"/static/b55a7b7b4c94ff63959b618e5ae1fa31/56d15/listComprehension.png 200w,\n/static/b55a7b7b4c94ff63959b618e5ae1fa31/d9f49/listComprehension.png 400w,\n/static/b55a7b7b4c94ff63959b618e5ae1fa31/a27c6/listComprehension.png 700w\"\n        sizes=\"(max-width: 700px) 100vw, 700px\"\n        style=\"width:100%;height:100%;margin:0;vertical-align:middle;position:absolute;top:0;left:0;\"\n        loading=\"lazy\"\n        decoding=\"async\"\n      />\n  </a>\n    </span></p>\n<p>As we can see, list comprehension is concise and more readable.</p>\n<p>Let’s create another list - this time however, we will include an <em>if</em> clause after the <em>for</em> loop in order to define a condition.</p>\n<pre class=\"grvsc-container synthwave-84\" data-language=\"py\" data-index=\"3\"><code class=\"grvsc-code\"><span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"1\"></span><span class=\"grvsc-source\"><span class=\"mtk15\">squared </span><span class=\"mtk12\">=</span><span class=\"mtk15\"> [num </span><span class=\"mtk10\">*</span><span class=\"mtk15\"> num </span><span class=\"mtk10\">for</span><span class=\"mtk15\"> num </span><span class=\"mtk10\">in</span><span class=\"mtk15\"> </span><span class=\"mtk6\">range</span><span class=\"mtk15\">(</span><span class=\"mtk5\">5</span><span class=\"mtk15\">) </span><span class=\"mtk10\">if</span><span class=\"mtk15\"> num </span><span class=\"mtk10\">%</span><span class=\"mtk15\"> </span><span class=\"mtk5\">2</span><span class=\"mtk15\"> </span><span class=\"mtk10\">==</span><span class=\"mtk15\"> </span><span class=\"mtk5\">0</span><span class=\"mtk15\">]</span></span></span>\n<span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"2\"></span><span class=\"grvsc-source\"></span></span>\n<span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"3\"></span><span class=\"grvsc-source\"><span class=\"mtk6\">print</span><span class=\"mtk15\">(squared)</span></span></span>\n<span class=\"grvsc-line\"><span class=\"grvsc-gutter-pad\"></span><span class=\"grvsc-gutter grvsc-line-number\" aria-hidden=\"true\" data-content=\"4\"></span><span class=\"grvsc-source\"><span class=\"mtk4 mtki\"># [0, 4, 16]</span></span></span></code></pre>\n<style class=\"grvsc-styles\">\n  .grvsc-container {\n    overflow: auto;\n    position: relative;\n    -webkit-overflow-scrolling: touch;\n    padding-top: 1rem;\n    padding-top: var(--grvsc-padding-top, var(--grvsc-padding-v, 1rem));\n    padding-bottom: 1rem;\n    padding-bottom: var(--grvsc-padding-bottom, var(--grvsc-padding-v, 1rem));\n    border-radius: 8px;\n    border-radius: var(--grvsc-border-radius, 8px);\n    font-feature-settings: normal;\n    line-height: 1.4;\n  }\n  \n  .grvsc-code {\n    display: table;\n  }\n  \n  .grvsc-line {\n    display: table-row;\n    box-sizing: border-box;\n    width: 100%;\n    position: relative;\n  }\n  \n  .grvsc-line > * {\n    position: relative;\n  }\n  \n  .grvsc-gutter-pad {\n    display: table-cell;\n    padding-left: 0.75rem;\n    padding-left: calc(var(--grvsc-padding-left, var(--grvsc-padding-h, 1.5rem)) / 2);\n  }\n  \n  .grvsc-gutter {\n    display: table-cell;\n    -webkit-user-select: none;\n    -moz-user-select: none;\n    user-select: none;\n  }\n  \n  .grvsc-gutter::before {\n    content: attr(data-content);\n  }\n  \n  .grvsc-source {\n    display: table-cell;\n    padding-left: 1.5rem;\n    padding-left: var(--grvsc-padding-left, var(--grvsc-padding-h, 1.5rem));\n    padding-right: 1.5rem;\n    padding-right: var(--grvsc-padding-right, var(--grvsc-padding-h, 1.5rem));\n  }\n  \n  .grvsc-source:empty::after {\n    content: ' ';\n    -webkit-user-select: none;\n    -moz-user-select: none;\n    user-select: none;\n  }\n  \n  .grvsc-gutter + .grvsc-source {\n    padding-left: 0.75rem;\n    padding-left: calc(var(--grvsc-padding-left, var(--grvsc-padding-h, 1.5rem)) / 2);\n  }\n  \n  /* Line transformer styles */\n  \n  .grvsc-has-line-highlighting > .grvsc-code > .grvsc-line::before {\n    content: ' ';\n    position: absolute;\n    width: 100%;\n  }\n  \n  .grvsc-line-diff-add::before {\n    background-color: var(--grvsc-line-diff-add-background-color, rgba(0, 255, 60, 0.2));\n  }\n  \n  .grvsc-line-diff-del::before {\n    background-color: var(--grvsc-line-diff-del-background-color, rgba(255, 0, 20, 0.2));\n  }\n  \n  .grvsc-line-number {\n    padding: 0 2px;\n    text-align: right;\n    opacity: 0.7;\n  }\n  \n  .synthwave-84 { background-color: #262335; }\n  .synthwave-84 .mtki { font-style: italic; }\n  .synthwave-84 .mtk15 { color: #FF7EDBFF; }\n  .synthwave-84 .mtk12 { color: #FFFFFFEE; }\n  .synthwave-84 .mtk16 { color: #FF8B39; }\n  .synthwave-84 .mtk10 { color: #FEDE5D; }\n  .synthwave-84 .mtk6 { color: #36F9F6; }\n  .synthwave-84 .mtk5 { color: #F97E72; }\n  .synthwave-84 .mtk4 { color: #848BBD; }\n  .synthwave-84 .grvsc-line-highlighted::before {\n    background-color: var(--grvsc-line-highlighted-background-color, rgba(255, 255, 255, 0.1));\n    box-shadow: inset var(--grvsc-line-highlighted-border-width, 4px) 0 0 0 var(--grvsc-line-highlighted-border-color, rgba(255, 255, 255, 0.5));\n  }\n</style>","frontmatter":{"title":"Creating Python Lists Using List Comprehension","date":"2021-08-18"}}},"pageContext":{"slug":"/creating-python-lists-using-list-comprehension/","prev":{"fields":{"slug":"/an-introduction-to-python-functions/"},"frontmatter":{"modules":null}},"next":{"fields":{"slug":"/lambda-expressions-in-python/"},"frontmatter":{"modules":null}}}},
    "staticQueryHashes": ["3159585216"]}