<i>Python 3 is slower, offers no compelling features</i><p>Python 3.0 was slower than 2.7 due to several key bits being implemented in pure Python in 3.0. Since the 3.0 release (remember, Python&#x27;s on 3.5 now) things that needed it have been rewritten in C, and as of Python 3.3 the speed difference is one. Also, on Python 3.3+ strings use anywhere from one-half to one-fourth the memory they used to.<p>As for &quot;no compelling features&quot;, well...<p>* New, better-organized standard library modules for quite a few things including networking<p>* Extended iterable unpacking<p>* concurrent.futures<p>* Improved generators and coroutines with &#x27;yield from&#x27;<p>* asyncio and async&#x2F;await support in the language itself<p>* The matrix-multiplication operator supported at the language level (kinda important for all the math&#x2F;science stacks using Python)<p>* Exception chaining and &#x27;raise from&#x27;<p>* The simplified, Python-accessible rewritten import system<p>etc., etc., etc.