Have you used Future in the asyncio asynchronous library?

In asyncio, the Future object represents a promise that the result of an asynchronous operation will be available in the future. Future is used to track the state and obtain the result of a task.

Main points of using Future:

• A Future is created and returned when an asynchronous operation is started.
• Callbacks can be added, which will be called upon the completion of the Future.
• A Future can be in a pending state, successfully completed, or with an error.

In asyncio, coroutines and tasks (Task) are more commonly used, which wrap a Future, but sometimes it is necessary to work directly with Future, for example, when integrating with low-level APIs or creating custom asynchronous primitives.

Example of creating and using a Future:

import asyncio

def set_result_later(fut):
    # Set the result after 1 second
    asyncio.get_event_loop().call_later(1, fut.set_result, 'Done')

async def main():
    loop = asyncio.get_event_loop()
    fut = loop.create_future()
    set_result_later(fut)
    result = await fut
    print(result)  # Will print: Done

asyncio.run(main())

Thus, a Future is a low-level object for managing the results of asynchronous operations in asyncio.