as_completed

Create an iterator of awaitables or their results in completion order.

Run the supplied awaitables concurrently. The returned object can be
iterated to obtain the results of the awaitables as they finish.

The object returned can be iterated as an asynchronous iterator or
a plain iterator.  When asynchronous iteration is used, the
originally-supplied awaitables are yielded if they are tasks or
futures.  This makes it easy to correlate previously-scheduled tasks
with their results:

    ipv4_connect = create_task(open_connection("127.0.0.1", 80))
    ipv6_connect = create_task(open_connection("::1", 80))
    tasks = [ipv4_connect, ipv6_connect]

    async for earliest_connect in as_completed(tasks):
        # earliest_connect is done. The result can be obtained by
        # awaiting it or calling earliest_connect.result()
        reader, writer = await earliest_connect

        if earliest_connect is ipv6_connect:
            print("IPv6 connection established.")
        else:
            print("IPv4 connection established.")

During asynchronous iteration, implicitly-created tasks will be
yielded for supplied awaitables that aren't tasks or futures.

When used as a plain iterator, each iteration yields a new coroutine
that returns the result or raises the exception of the next completed
awaitable.  This pattern is compatible with Python versions older than
3.13:

    ipv4_connect = create_task(open_connection("127.0.0.1", 80))
    ipv6_connect = create_task(open_connection("::1", 80))
    tasks = [ipv4_connect, ipv6_connect]

    for next_connect in as_completed(tasks):
        # next_connect is not one of the original task objects. It must
        # be awaited to obtain the result value or raise the exception
        # of the awaitable that finishes next.
        reader, writer = await next_connect

A TimeoutError is raised if the timeout occurs before all awaitables
are done.  This is raised by the async for loop during asynchronous
iteration or by the coroutines yielded during plain iteration.