Handling coroutines with Asyncio

We saw, in the course of the various examples presented, that when a program becomes very long and complex, it is convenient to divide it into subroutines, each of which realizes a specific task for which it implements a suitable algorithm. The subroutine cannot be executed independently, but only at the request of the main program, which is then responsible for coordinating the use of subroutines. Coroutines are a generalization of the subroutine. Like a subroutine, the coroutine computes a single computational step, but unlike subroutines, there is no main program that can be used to coordinate the results. This is because the coroutines link themselves together to form a pipeline without any supervising function responsible for calling them in a particular order. In a coroutine, the execution point can be suspended and resumed later after keeping track of its local state in the intervening time. Having a pool of coroutines, it is possible to interleave...