Daniel Arbuckle's Mastering Python

Python coroutines

In Python coroutines, the pause and resume points are await expressions; this is how we call other coroutines. Every time we want to perform a function, we call a coroutine from inside another coroutine. We wait for the coroutine we want to call.

The semantics of the code work as if they call a function from inside another function. The other coroutine runs until it returns and we get back the return value. That's how the code behaves, but what it actually does is quite a bit more interesting.