If you subscribe to versioning schemes like for instance semantic versioning [1], then the major version number must be incremented "if any backwards incompatib

If you subscribe to versioning schemes like for instance semantic versioning [1], then the major version number must be incremented "if any backwards incompatible changes are introduced to the public API". In that sense, the change from Python 2 to 3 could warrant it. [1] http://semver.org/ http://semver.org/