What is the difference between concurrent.futures and asyncio.futures?

The asyncio documentation covers the differences:

class asyncio.Future(*, loop=None)

This class is almost compatible with concurrent.futures.Future.

Differences:

• result() and exception() do not take a timeout argument and raise an exception when the future isn’t done yet.
• Callbacks registered with add_done_callback() are always called via the event loop’s call_soon_threadsafe().
• This class is not compatible with the wait() and as_completed() functions in the concurrent.futures package.

This class is not thread safe.

Basically, if you’re using ThreadPoolExecutor or ProcessPoolExecutor, or want to use a Future directly for thread-based or process-based concurrency, use concurrent.futures.Future. If you’re using asyncio, use asyncio.Future.