"""
Once asyncio has created an event loop,an application registers the functions to call back when a specific event happens:
 as time passes, a file descriptor is ready to be read,or a socket is ready to be written. That type of function is
 called a coroutine. It is a particular type of function that can give back control to the caller so that the event loop
  can continue running.
"""
import asyncio

# Adding the async keyword makes this a coroutine object
async def hello_world():
    print('Hello world')
    return 42


hello_world_coroutine = hello_world()
print(hello_world_coroutine)

event_loop = asyncio.get_event_loop()
try:
    print('Entering the event loop')
    result = event_loop.run_until_complete(hello_world_coroutine)
    print(result)
finally:
    event_loop.close()