single thread cooperative multitasking

test 2

Awaitable

Coroutine

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async def: pass

A coroutine execution returns a coroutine object. Simply calling a coroutine will not schedule it to be executed

Coroutine can be awaited and it makes the execution synchronous from the caller perspective

Can be run with :

• await
• asyncio.run()
• asyncio.create_task() to run coroutines concurrently as asyncio tasks

Task

Tasks are used to schedule coroutines concurrently

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async def coroutine():
    return 42

async def main():
    # Schedule nested() to run soon concurrently with "main()".
    task = asyncio.create_task(coroutine())
    # or task = asyncio.ensure_future(coroutine())

asyncio.run(main())

Future

A Future is a special low-level awaitable

Future objects in asyncio are needed to allow callback-based code to be used with async/await.

Running an asyncio program

• Using asyncio.run(coroutine())
• Creates an event loop and manages awaiting and closing the pool
• Only one pool allowed at the same time by thread