python changes and this book this appendix briefly summarizes changes made in recent releases of python organized by the book editions where they first appearedand gives links to their coverage in this book it is intended as reference for both readers of prior editionsas well as developers migrating from prior python releases here' how changes in python relate to this book' recent editionsthis fifth edition of covers python and the fourth edition of covered python and (with some featuresthe third edition of covered python the first and second editions of and covered pythons and the predecessor of this book ' programming pythoncovered python henceto see changes made in just this fifth editionsee the python and changes listed ahead for changes incorporated into both the fourth and fifth editions (that issince the third)also see python and changes here third edition language changes are listed very briefly toothough this seems of only historical value today also note that this appendix focuses on major changes and book impactsand is not intended as complete guide to python' evolution for the fuller story on changes applied in each new python releaseconsult the "what' newdocuments that are part of its standard documentation setand available at the documentation page of python org covers python documentation and its manuals set major / differences much of this appendix relates python changes to book coverage if you're instead looking for quick summary of the most prominent / distinctionsthe following may suffice note that this section primarily compares the latest and releases -- and many features are not listed here because they were either also added