Python 3.7.0rc1 and 3.6.6rc1 are now available. 3.7.0rc1 is the final planned release preview of Python 3.7, the next feature release of Python. 3.6.6rc1 is the release preview of the next maintenance release of Python 3.6, the current release of Python. Assuming no critical problems are found prior to 2018-06-27, the scheduled release dates for 3.7.0 and 3.6.6, no code changes are planned between these release candidates and the final releases. These release candidates are intended to give you the opportunity to test the new features and bug fixes in 3.7.0 and 3.6.6 and to prepare your projects to support them. We strongly encourage you to test your projects and report issues found to bugs.python.org as soon as possible. Please keep in mind that these are preview releases and, thus, their use is not recommended for production environments. Attention macOS users: there is now a new installer variant for macOS 10.9+ that includes a built-in version of Tcl/Tk 8.6. This variant will become the default version when 3.7.0 releases. Check it out!
You can find these releases and more information here:
Python core development news and information.