Without listing any of the modules or improvements that are in the standard library in 3 but backported as PyPI modules to 2 (of which there are many), here are

Without listing any of the modules or improvements that are in the standard library in 3 but backported as PyPI modules to 2 (of which there are many), here are the features that I actually use in Python 3: unicode handling that isn't insane, function annotations, async improvements, exception chaining, enums, single-dispatch generics, better SSL support, generator delegation, better int-bytes conversion support, unittest module improvements. The key point is that 2.7 is a language frozen in time, while 3.4+ is continuing to develop and improve. And most of the hand-wringing was before the critical mass of third-party modules was ported to 3.x. https://docs.python.org/3/whatsnew/3.4.html https://docs.python.org/3/whatsnew/3.4.html https://docs.python.org/3/whatsnew/3.3.html https://docs.python.org/3/whatsnew/3.3.html https://docs.python.org/3/whatsnew/3.2.html https://docs.python.org/3/whatsnew/3.2.html https://docs.python.org/3/whatsnew/3.1.html https://docs.python.org/3/whatsnew/3.1.html https://docs.python.org/3/whatsnew/3.0.html https://docs.python.org/3/whatsnew/3.0.html