Python 3.7.4rc1 and 3.6.9rc1 are now available. 3.7.4rc1 is the release preview of the next maintenance release of Python 3.7, the latest feature release of Python. 3.6.9rc1 is the release preview of the first security-fix release of Python 3.6. Assuming no critical problems are found prior to 2019-06-28, 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 security and bug fixes in 3.7.4 and security fixes in 3.6.9. 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.
You can find the release files, a link to their changelogs, and more information here:
Python core development news and information.