concurrent.futures 和 asyncio.futures 有什么区别？

Question

澄清一下这个问题的原因：

1. 使用同名的两个模块会造成混淆。它们代表什么使它们与众不同？

2. 哪些任务一个人可以解决而另一个人不能，反之亦然？

Answer 1

来自docs：

[asyncio provides a] Future class that mimics the one in the concurrent.futures module, but adapted for use with the event loop;

Answer 2

asyncio documentation涵盖了不同之处：

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.

基本上，如果您正在使用 ThreadPoolExecutor 或 ProcessPoolExecutor，或者想直接使用 Future 进行基于线程或基于进程的并发，请使用 concurrent.futures.Future.如果您使用 asyncio，请使用 asyncio.Future。