async in general gets you concurrency. async def/await is syntactic sugar around generators built with __iter__ and __next__. It is totally possible to do coop

async in general gets you concurrency. async def/await is syntactic sugar around generators built with __iter__ and __next__. It is totally possible to do cooperative multitasking with __iter__, __next__, yield, yield from. What this is doing is painting in some of the missing corners of the syntax. Anything you can do with a list comprehension can be done with a for loop, less tersely, often but not always less readably (choose wisely). This new syntax allows you to write comprehensions with asynchronous behavior that in 3.5 and earlier requires you to write a loop. Progress is in the eye of the beholder. "Code is read more often than it is written." Please chose the most readable form.