--- title: Help test Python 3.15! | daily.dev description: The second and final Python 3.15 release candidate is out, with the full release scheduled for October 1, 2026. Library maintainers are urged to test their... canonical: https://daily.dev/posts/help-test-python-3-15--pldj3q0mx twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Help test Python 3.15! | daily.dev og:description: The second and final Python 3.15 release candidate is out, with the full release scheduled for October 1, 2026. Library maintainers are urged to test their... og:url: https://daily.dev/posts/help-test-python-3-15--pldj3q0mx og:image: https://api.daily.dev/og/posts/pldJ3Q0mX.png og:image:alt: Help test Python 3.15! 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. # Help test Python 3.15! **[Planet Python](https://daily.dev/sources/planetpython)** · 3 min read · 0 upvotes · 0 comments ## Summary The second and final Python 3.15 release candidate is out, with the full release scheduled for October 1, 2026. Library maintainers are urged to test their projects against 3.15 now to catch removals, changes, and compatibility issues before launch, and to publish binary wheels for the release candidates. Guidance is given for testing with actions/setup-python on GitHub Actions using allow-prereleases, adding the Python 3.15 Trove classifier, and a note that there will be no ABI changes for the rest of the 3.15 series. ## 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 officially being released? Python 3.15.0 is scheduled for full release on October 1, 2026, according to the PEP 790 release schedule. The first release candidate came out on August 4, 2026, and the second and final release candidate was released on September 1, 2026, giving maintainers a final window to test compatibility before launch. _Track Python 3.15 rollout news on daily.dev while preparing your library for the release._ ### How do I test my project against Python 3.15 release candidates in GitHub Actions? Add 3.15 with allow-prereleases: true to your workflow's python-version matrix when using actions/setup-python. Alternatively, use 3.15-dev without the allow-prereleases flag, though pairing 3.15 with allow-prereleases means the same matrix entry keeps working once 3.15.0 final ships in October, without needing a workflow change. _Developers wiring up prerelease Python testing follow CI tooling changes like this on daily.dev._ ### Will Python 3.15 release candidates break ABI compatibility for extension modules? No, there will be no ABI changes from the second release candidate onward through the rest of the Python 3.15 series, so the goal is to keep code changes to a minimum for the final release. Maintainers with extension modules are encouraged to publish binary wheels built against the 3.15 release candidates so dependent projects can test and prepare early. _Maintainers tracking ABI stability across Python releases follow updates like this on 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 3.15.0a8, 3.14.4 and 3.13.13 are out\!](https://daily.dev/posts/python-3-15-0a8-3-14-4-and-3-13-13-are-out--fpknzjqcr) · Python Insider · 29 upvotes · 1 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 --- Tags: [#python](https://daily.dev/tags/python), [#testing](https://daily.dev/tags/testing), [#cicd](https://daily.dev/tags/cicd), [#github-actions](https://daily.dev/tags/github-actions) [View this post on daily.dev](https://daily.dev/posts/help-test-python-3-15--pldj3q0mx) ```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":"Help test Python 3.15!","url":"https://daily.dev/posts/help-test-python-3-15--pldj3q0mx","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/help-test-python-3-15--pldj3q0mx"},"datePublished":"2026-09-01T16:51:46.650Z","dateModified":"2026-09-02T14:33:27.160Z","description":"The second and final Python 3.15 release candidate is out, with the full release scheduled for October 1, 2026. 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