Hands-On Reactive Programming with Python

Coroutines

Coroutines are another building block of AsyncIO. Coroutines were already covered in detail previously in this chapter. A coroutine is basically a generator with syntactic sugar. A coroutine is an asynchronous function that can be interrupted and resumed at specific locations. A coroutine is declared the same way as a function, but with the async keyword prefixed:

import datetimeasync def wait(delay):    now = datetime.datetime.now()    print("wait for {} seconds at {}:{}:{}".format(        delay, now.hour, now.minute, now.second))    return True

This coroutine just returns True for now. The first big difference between a coroutine and a regular function is the fact that its code is not immediately executed when the coroutine is called. Instead, ...