Can you explain what coroutines are in the Asyncio library for asynchronous programming?

Coroutines in the Asyncio library are special functions that can suspend their execution, allowing other tasks to run during that time, and then resume work. This is the main mechanism for asynchronous programming in Python.

A coroutine is defined using the async def keyword, and inside it, you can use await to wait for the completion of other asynchronous operations without blocking the main thread.

Example of a coroutine:

import asyncio

async def say_hello():
    print('Hello')
    await asyncio.sleep(1)  # suspends the coroutine for 1 second
    print('World')

asyncio.run(say_hello())

Here, asyncio.sleep is an asynchronous delay that does not block the execution of other coroutines in the event loop. Thus, coroutines allow writing asynchronous code that looks sequential but efficiently utilizes waiting time.