I believe they said they were going to try very hard to not do major backwards compatible breaking changes again.<p>&gt; My current expectation is that Python 4.0 will merely be &quot;the release that comes after Python 3.9&quot;. That&#x27;s it. No profound changes to the language, no major backwards compatibility breaks - going from Python 3.9 to 4.0 should be as uneventful as going from Python 3.3 to 3.4 (or from 2.6 to 2.7). I even expect the stable Application Binary Interface (as first defined in PEP 384) to be preserved across the boundary.<p><a href="http:&#x2F;&#x2F;www.curiousefficiency.org&#x2F;posts&#x2F;2014&#x2F;08&#x2F;python-4000.html" rel="nofollow">http:&#x2F;&#x2F;www.curiousefficiency.org&#x2F;posts&#x2F;2014&#x2F;08&#x2F;python-4000.h...</a> (which was linked by Guido from his Twitter).