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<title data-rh="true">Loop | Langflow Documentation</title><meta data-rh="true" name="viewport" content="width=device-width,initial-scale=1"><meta data-rh="true" name="twitter:card" content="summary_large_image"><meta data-rh="true" property="og:url" content="https://docs.langflow.org/loop"><meta data-rh="true" property="og:locale" content="en"><meta data-rh="true" name="docusaurus_locale" content="en"><meta data-rh="true" name="docsearch:language" content="en"><meta data-rh="true" name="docusaurus_version" content="current"><meta data-rh="true" name="docusaurus_tag" content="docs-default-current"><meta data-rh="true" name="docsearch:version" content="current"><meta data-rh="true" name="docsearch:docusaurus_tag" content="docs-default-current"><meta data-rh="true" property="og:title" content="Loop | Langflow Documentation"><meta data-rh="true" name="description" content="The Loop component iterates over a list of input by passing individual items to other components attached at the Item output port until there are no items left to process."><meta data-rh="true" property="og:description" content="The Loop component iterates over a list of input by passing individual items to other components attached at the Item output port until there are no items left to process."><link data-rh="true" rel="icon" href="/img/favicon.ico"><link data-rh="true" rel="canonical" href="https://docs.langflow.org/loop"><link data-rh="true" rel="alternate" href="https://docs.langflow.org/loop" hreflang="en"><link data-rh="true" rel="alternate" href="https://docs.langflow.org/loop" hreflang="x-default"><link data-rh="true" rel="preconnect" href="https://UZK6BDPCVY-dsn.algolia.net" crossorigin="anonymous"><script data-rh="true" type="application/ld+json">{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Loop","item":"https://docs.langflow.org/loop"}]}</script><link rel="preconnect" href="https://www.google-analytics.com">
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<p>The <strong>Loop</strong> component iterates over a list of input by passing individual items to other components attached at the <strong>Item</strong> output port until there are no items left to process.
Then, the <strong>Loop</strong> component passes the aggregated result of all looping to the component connected to the <strong>Done</strong> port.</p>
<h2 class="anchor anchorTargetHideOnScrollNavbar_vjPI" id="the-looping-process">The looping process<a href="#the-looping-process" class="hash-link" aria-label="Direct link to The looping process" title="Direct link to The looping process" translate="no">​</a></h2>
<p>The <strong>Loop</strong> component is like a miniature flow within your flow.
Here&#x27;s a breakdown of the looping process:</p>
<ol>
<li class="">
<p>Accepts a list of <a class="" href="/data-types#data"><code>Data</code></a> or <a class="" href="/data-types#dataframe"><code>DataFrame</code></a> objects, such as a CSV file, through the <strong>Loop</strong> component&#x27;s <strong>Inputs</strong> port.</p>
</li>
<li class="">
<p>Splits the input into individual items. For example, a CSV file is broken down by rows.</p>
<p>Specifically, the <strong>Loop</strong> component repeatedly extracts items by <code>text</code> key in the <code>Data</code> or <code>DataFrame</code> objects until there are no more items to extract.
Each <code>item</code> output is a <code>Data</code> objects.</p>
</li>
<li class="">
<p>Iterates over each <code>item</code> by passing them to the <strong>Item</strong> output port.</p>
<p>This port connects to one or more components that perform actions on each item.
The final component in the <strong>Item</strong> loop connects back to the <strong>Loop</strong> component&#x27;s <strong>Looping</strong> port to process the next item.</p>
<p>Only one component connects to the <strong>Item</strong> port, but you can pass the data through as many components as you need, as long as the last component in the chain connects back to the <strong>Looping</strong> port.</p>
<p>The <a class="" href="/if-else"><strong>If-Else</strong> component</a> isn&#x27;t compatible with the <strong>Loop</strong> component.
For more information, see <a href="#conditional-looping" class="">Conditional looping</a>.</p>
</li>
<li class="">
<p>After processing all items, the results are aggregated into a single <code>Data</code> object that is passed from the <strong>Loop</strong> component&#x27;s <strong>Done</strong> port to the next component in the flow.</p>
</li>
</ol>
<p>The following simplified Python code summarizes how the <strong>Loop</strong> component works.
This <em>isn&#x27;t</em> the actual component code; it is only meant to help you understand the general process.</p>
<div class="ch-codeblock not-prose" data-ch-theme="github-dark"><div class="ch-code-wrapper ch-code" data-ch-measured="false"><code class="ch-code-scroll-parent"><br><div><span class="ch-code-line-number">_<!-- -->10</span><div style="display:inline-block;margin-left:16px"><span>for i in input: # Receive input data as a list</span></div></div><div><span class="ch-code-line-number">_<!-- -->10</span><div style="display:inline-block;margin-left:16px"><span> process_item(i) # Process each item through components connected at the Item port</span></div></div><div><span class="ch-code-line-number">_<!-- -->10</span><div style="display:inline-block;margin-left:16px"><span> if has_more_items():</span></div></div><div><span class="ch-code-line-number">_<!-- -->10</span><div style="display:inline-block;margin-left:16px"><span> continue # Loop back to Looping port to process the next item</span></div></div><div><span class="ch-code-line-number">_<!-- -->10</span><div style="display:inline-block;margin-left:16px"><span> else:</span></div></div><div><span class="ch-code-line-number">_<!-- -->10</span><div style="display:inline-block;margin-left:16px"><span> break # Exit the loop when no more items are left</span></div></div><div><span class="ch-code-line-number">_<!-- -->10</span><div style="display:inline-block;margin-left:16px"><span></span></div></div><div><span class="ch-code-line-number">_<!-- -->10</span><div style="display:inline-block;margin-left:16px"><span>done = aggregate_results() # Compile all returned items</span></div></div><div><span class="ch-code-line-number">_<!-- -->10</span><div style="display:inline-block;margin-left:16px"><span></span></div></div><div><span class="ch-code-line-number">_<!-- -->10</span><div style="display:inline-block;margin-left:16px"><span>print(done) # Send the aggregated results from the Done port to another component</span></div></div><br></code></div></div>
<h2 class="anchor anchorTargetHideOnScrollNavbar_vjPI" id="loop-example">Loop example<a href="#loop-example" class="hash-link" aria-label="Direct link to Loop example" title="Direct link to Loop example" translate="no">​</a></h2>
<p>In the follow example, the <strong>Loop</strong> component iterates over a CSV file until there are no rows left to process.
In this case, the <strong>Item</strong> port passes each row to a <strong>Type Convert</strong> component to convert the row into a <code>Message</code> object, passes the <code>Message</code> to a <strong>Structured Output</strong> component to be processed into structured data that is then passed back to the <strong>Loop</strong> component&#x27;s <strong>Looping</strong> port.
After processing all rows, the <strong>Loop</strong> component loads the aggregated list of structured data into a Chroma DB database through the <strong>Chroma DB</strong> component connected to the <strong>Done</strong> port.</p>
<p><img decoding="async" loading="lazy" alt="Loop CSV parser" src="/assets/images/component-loop-csv-66c1b53f0722b36a900632806cb32d78.png" width="3876" height="3300" class="img_ev3q"></p>
<div class="theme-admonition theme-admonition-tip admonition_xJq3 alert alert--success"><div class="admonitionHeading_Gvgb"><span class="admonitionIcon_Rf37"><svg viewBox="0 0 12 16"><path fill-rule="evenodd" d="M6.5 0C3.48 0 1 2.19 1 5c0 .92.55 2.25 1 3 1.34 2.25 1.78 2.78 2 4v1h5v-1c.22-1.22.66-1.75 2-4 .45-.75 1-2.08 1-3 0-2.81-2.48-5-5.5-5zm3.64 7.48c-.25.44-.47.8-.67 1.11-.86 1.41-1.25 2.06-1.45 3.23-.02.05-.02.11-.02.17H5c0-.06 0-.13-.02-.17-.2-1.17-.59-1.83-1.45-3.23-.2-.31-.42-.67-.67-1.11C2.44 6.78 2 5.65 2 5c0-2.2 2.02-4 4.5-4 1.22 0 2.36.42 3.22 1.19C10.55 2.94 11 3.94 11 5c0 .66-.44 1.78-.86 2.48zM4 14h5c-.23 1.14-1.3 2-2.5 2s-2.27-.86-2.5-2z"></path></svg></span>tip</div><div class="admonitionContent_BuS1"><p>For more examples of the <strong>Loop</strong> component, try the <strong>Research Translation Loop</strong> template in Langflow, or see the video tutorial <a href="https://www.youtube.com/watch?v=9Wx7WODSKTo" target="_blank" rel="noopener noreferrer" class="">Mastering the Loop Component &amp; Agentic RAG in Langflow</a>.</p></div></div>
<h2 class="anchor anchorTargetHideOnScrollNavbar_vjPI" id="conditional-looping">Conditional looping<a href="#conditional-looping" class="hash-link" aria-label="Direct link to Conditional looping" title="Direct link to Conditional looping" translate="no">​</a></h2>
<p>The <a class="" href="/if-else"><strong>If-Else</strong> component</a> isn&#x27;t compatible with the <strong>Loop</strong> component.
If you need conditional loop events, redesign your flow to process conditions before the loop.
For example, if you are looping over a <code>DataFrame</code>, you could use multiple <a class="" href="/dataframe-operations"><strong>DataFrame Operations</strong> components</a> to conditionally filter data, and then run separate loops on each set of filtered data.</p>
<p><img decoding="async" loading="lazy" alt="A flow with conditional looping." src="/assets/images/conditional-looping-756b330b8dc690b3dab1c44cc2fb05db.png" width="1482" height="673" class="img_ev3q"></p></div></article><nav class="docusaurus-mt-lg pagination-nav" aria-label="Docs pages"><a class="pagination-nav__link pagination-nav__link--prev" href="/if-else"><div class="pagination-nav__sublabel">Previous</div><div class="pagination-nav__label">If-Else</div></a><a class="pagination-nav__link pagination-nav__link--next" href="/notify-and-listen"><div class="pagination-nav__sublabel">Next</div><div class="pagination-nav__label">Notify and Listen</div></a></nav></div></div><div class="col col--3"><div class="tableOfContents_bqdL thin-scrollbar theme-doc-toc-desktop"><ul class="table-of-contents table-of-contents__left-border"><li><a href="#the-looping-process" class="table-of-contents__link toc-highlight">The looping process</a></li><li><a href="#loop-example" class="table-of-contents__link toc-highlight">Loop example</a></li><li><a href="#conditional-looping" class="table-of-contents__link toc-highlight">Conditional looping</a></li></ul></div></div></div></div></main></div></div></div><footer class="theme-layout-footer footer"><div class="container container-fluid"><div class="row footer__links"><div class="theme-layout-footer-column col footer__col"><div class="footer__title"></div><ul class="footer__items clean-list"><li class="footer__item"><div class="footer-links">
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