Python 3.7.0b1 is the first of four planned beta previews of Python 3.7, the next feature release of Python. This preview marks the end of the feature development phase for 3.7. Beta releases are intended to give you the opportunity to test new features and bug fixes and to prepare your projects to support the new feature release. We strongly encourage you to test your projects with 3.7 during the beta phase and report issues found to bugs.python.org as soon as possible. While the release is feature complete entering the beta phase, it is possible that features may be modified or, in rare cases, deleted up until the start of the release candidate phase. Please keep in mind that this is a preview release and its use is not recommended for production environments. The next preview release, 3.7.0b2, is planned for 2018-02-26. You can find Python 3.7.0b1 and more information here:
Python core development news and information.