Introduction to Coroutines

What is a coroutine?

A coroutine is syntactically like a generator. In a coroutine, the yield keyword appears at the right side of an expression. For example:

x = yield

If there’s no expression besides yield, the coroutine may or may not produce any value.

In place of using the next() method, for coroutines to receive the data, a caller calls the send() function as:

caller.send(x)

💡 Remember, no data may go in or out through the yield keyword.

Bringing upgrades to Python generators led to the advent of coroutines.

Generator as a coroutine

Let’s start off with an example.