--- title: Python 3.15's Unpacking Operator Allows Flattening Lists... description: The unpacking operator inside a list comprehension can flatten a list of lists. The classic approach needs two nested for loops, written as 'x for y in my_list... canonical: https://daily.dev/posts/python-3-15-s-unpacking-operator-allows-flattening-lists-easily-domvxkyna twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Python 3.15's Unpacking Operator Allows Flattening Lists Easily | daily.dev og:description: The unpacking operator inside a list comprehension can flatten a list of lists. The classic approach needs two nested for loops, written as 'x for y in my_list... og:url: https://daily.dev/posts/python-3-15-s-unpacking-operator-allows-flattening-lists-easily-domvxkyna og:image: https://api.daily.dev/og/posts/DOmvxkyNA.png og:image:alt: Python 3.15's Unpacking Operator Allows Flattening Lists Easily og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Python 3.15's Unpacking Operator Allows Flattening Lists Easily **[NeuralNine](https://daily.dev/sources/neuralnine)** · 1 min read · 2 upvotes · 0 comments ## Summary The unpacking operator inside a list comprehension can flatten a list of lists. The classic approach needs two nested for loops, written as 'x for y in my_list for x in y', which the speaker finds confusing because of the ordering. The new approach writes a single comprehension, 'x for x in my_lists', and then unpacks x, which the speaker says has the exact same effect. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How do I flatten a list of lists in Python 3.15 using the unpacking operator in a comprehension? Write a single list comprehension like 'x for x in my_lists' and then unpack x with the unpacking operator, which flattens the nested list without needing two for loops. This replaces the classic double for-loop form 'x for y in my_list for x in y', which requires writing 'for y' before 'for x' even though the intuitive reading order is reversed. _Developers tracking new Python syntax changes can follow comprehension updates like this on daily.dev._ ## Similar posts on daily.dev - [How to Flatten a List of Lists in Python Quiz – Real Python](https://daily.dev/posts/how-to-flatten-a-list-of-lists-in-python-quiz-real-python-bfxfmiuno) · Real Python · 1 upvotes · 0 comments - [All iteration is the same in Python](https://daily.dev/posts/all-iteration-is-the-same-in-python-kmgraqtz3) · Planet Python · 1 upvotes · 0 comments --- Tags: [#python](https://daily.dev/tags/python) [View this post on daily.dev](https://daily.dev/posts/python-3-15-s-unpacking-operator-allows-flattening-lists-easily-domvxkyna) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Python 3.15's Unpacking Operator Allows Flattening Lists Easily","url":"https://daily.dev/posts/python-3-15-s-unpacking-operator-allows-flattening-lists-easily-domvxkyna","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/python-3-15-s-unpacking-operator-allows-flattening-lists-easily-domvxkyna"},"datePublished":"2026-10-25T13:01:05.452Z","dateModified":"2026-10-25T13:01:26.829Z","description":"The unpacking operator inside a list comprehension can flatten a list of lists. 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