--- title: Python 3.15.0 candidate 2 is here! | daily.dev description: Python 3.15.0 release candidate 2 is now available, marking the final planned RC before the official 3.15.0 release scheduled for October 1, 2026. It includes... canonical: https://daily.dev/posts/python-3-15-0-candidate-2-is-here--icqkeyymd twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Python 3.15.0 candidate 2 is here! | daily.dev og:description: Python 3.15.0 release candidate 2 is now available, marking the final planned RC before the official 3.15.0 release scheduled for October 1, 2026. It includes... og:url: https://daily.dev/posts/python-3-15-0-candidate-2-is-here--icqkeyymd og:image: https://api.daily.dev/og/posts/icQKeYYmD.png og:image:alt: Python 3.15.0 candidate 2 is here! 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 3.15.0 candidate 2 is here! **[Python Insider](https://daily.dev/sources/python)** · 4 min read · 4 upvotes · 0 comments ## Summary Python 3.15.0 release candidate 2 is now available, marking the final planned RC before the official 3.15.0 release scheduled for October 1, 2026. It includes about 144 bugfixes and no further ABI changes are expected. Maintainers of third-party packages are urged to test compatibility and publish wheels ahead of the final release. Major 3.15 features recap includes lazy imports (PEP 810), frozendict and sentinel built-in types, a dedicated profiling package with the Tachyon sampling profiler, frame pointers enabled by default, unpacking in comprehensions, UTF-8 as default encoding, TypedDict extra items, disjoint bases in the type system, a new PyBytesWriter C API, stable ABI for free-threaded builds, and a JIT compiler upgrade yielding 8-13% performance gains depending on platform. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### When is Python 3.15.0 final scheduled for release? Python 3.15.0 final is scheduled for release on October 1, 2026. This follows release candidate 2 (3.15.0rc2), which is the final planned release candidate and contains around 144 bugfixes, build improvements, and documentation changes from 76 contributors since rc1. No further ABI changes will occur in the 3.15 series after this point. _Track the Python 3.15 rollout on daily.dev so upgrade timing never catches your project off guard._ ### What are the major new features in Python 3.15 compared to 3.14? Python 3.15 introduces explicit lazy imports (PEP 810) for faster startup, a frozendict built-in type (PEP 814), a sentinel built-in type (PEP 661), a dedicated profiling package with the Tachyon sampling profiler (PEP 799), frame pointers enabled by default (PEP 831), unpacking in comprehensions (PEP 798), UTF-8 as the default encoding (PEP 686), TypedDict with typed extra items (PEP 728), and a JIT compiler upgrade giving 8-13% performance gains. _Developers evaluating the Python 3.15 upgrade path can follow feature breakdowns like this on daily.dev._ ### How much faster is the JIT compiler in Python 3.15? The JIT compiler in Python 3.15 has been significantly upgraded, delivering an 8-9% geometric mean performance improvement on x86-64 Linux compared to the standard interpreter, and a 12-13% speedup on AArch64 macOS compared to the tail-calling interpreter. The official Windows 64-bit binaries also now use the tail-calling interpreter, and macOS binaries install free-threading support by default. _Performance-focused Python teams weighing runtime upgrades can keep tabs on JIT gains via daily.dev._ ## Similar posts on daily.dev - [Python 3.15.0 candidate 1 is here\!](https://daily.dev/posts/python-3-15-0-candidate-1-is-here--fuskzufeb) · Python Insider · 29 upvotes · 4 comments - [Python 3.15.0 beta 4 is here\!](https://daily.dev/posts/python-3-15-0-beta-4-is-here--tlgvqqsmi) · Python Insider · 9 upvotes · 0 comments - [Python 3.15.0 beta 3 is here\!](https://daily.dev/posts/python-3-15-0-beta-3-is-here--kbews0asi) · Python Insider · 15 upvotes · 1 comments - [Python 3.15.0 beta 2 is here\!](https://daily.dev/posts/python-3-15-0-beta-2-is-here--byisq3xcx) · Python Insider · 5 upvotes · 0 comments --- Tags: [#python](https://daily.dev/tags/python), [#devops](https://daily.dev/tags/devops), [#cpython](https://daily.dev/tags/cpython) [View this post on daily.dev](https://daily.dev/posts/python-3-15-0-candidate-2-is-here--icqkeyymd) ```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 3.15.0 candidate 2 is here!","url":"https://daily.dev/posts/python-3-15-0-candidate-2-is-here--icqkeyymd","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/python-3-15-0-candidate-2-is-here--icqkeyymd"},"datePublished":"2026-09-01T12:13:06.647Z","dateModified":"2026-09-02T14:33:27.160Z","description":"Python 3.15.0 release candidate 2 is now available, marking the final planned RC before the official 3.15.0 release scheduled for October 1, 2026. 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