release candidate
A release candidate is a pre-release version of Python that becomes the final release unless critical bugs are found in testing. Release candidates come after the alpha and beta phases, when the codebase is feature-complete and only severe fixes are still applied.
The version naming follows PEP 440. Release candidates use the suffix rc, written as <major>.<minor>.<micro>rcN, where N starts at 1 and increments with each candidate. For example, 3.14.0rc1 is the first release candidate for Python 3.14.0. PEP 440 also accepts the shorter spelling c as equivalent to rc.
On CPython, you can check whether the running interpreter is a release candidate by reading sys.version_info.releaselevel, which is 'candidate' on a release candidate and 'final' on a published release.
Example
Say you’ve installed the Python 3.14.0rc1 interpreter. Checking the release level then identifies it as a release candidate:
>>> import sys
>>> sys.version_info.releaselevel
'candidate'
Related Resources
Tutorial
How Can You Install a Pre-Release Version of Python?
If you want to have a peek at what's coming in the next stable version of Python, then you can install a pre-release version. In this tutorial, you'll learn how to access the latest Python versions and help test them.
For additional information on related topics, take a look at the following resources:
- Python 3.14 Release Candidate Lands: Faster Code, Smarter Concurrency (Tutorial)
- Using Python's pip to Manage Your Projects' Dependencies (Tutorial)
- Managing Multiple Python Versions With pyenv (Tutorial)
- Run Python Versions in Docker: How to Try the Latest Python Release (Tutorial)
- Should You Update to the Latest Python Bugfix Version? (Tutorial)
- A Beginner's Guide to pip (Course)
- Using Python's pip to Manage Your Projects' Dependencies (Quiz)
- Start Managing Multiple Python Versions With pyenv (Course)
- Managing Multiple Python Versions With pyenv (Quiz)
