bpo-42230: Improve asyncio documentation regarding accepting sets vs iterables (GH-23073)

People call wait() and as_completed() with various non-set iterables,
a list should be the most common but there are others as well[1].

Considering typeshed also documents wait()[2] and as_completed()[3]
as accepting arbitrary iterables I think it's a good idea to document
the status quo better.

[1] https://github.com/aio-libs/aiokafka/pull/672
[2] https://github.com/python/typeshed/blob/620989bac572f30349b95590ebe81a73ce0fe862/stdlib/3/asyncio/tasks.pyi#L161
[3] https://github.com/python/typeshed/blob/620989bac572f30349b95590ebe81a73ce0fe862/stdlib/3/asyncio/tasks.pyi#L40

1 files changed, 2 insertions, 2 deletions

diff --git a/Lib/asyncio/tasks.py b/Lib/asyncio/tasks.py
index 8b05434..ad31f5d 100644
--- a/Lib/asyncio/tasks.py
+++ b/Lib/asyncio/tasks.py
@@ -373,7 +373,7 @@ ALL_COMPLETED = concurrent.futures.ALL_COMPLETED
 async def wait(fs, *, loop=None, timeout=None, return_when=ALL_COMPLETED):
     """Wait for the Futures and coroutines given by fs to complete.
 
-    The sequence futures must not be empty.
+    The fs iterable must not be empty.
 
     Coroutines will be wrapped in Tasks.
 
@@ -573,7 +573,7 @@ def as_completed(fs, *, loop=None, timeout=None):
     Note: The futures 'f' are not necessarily members of fs.
     """
     if futures.isfuture(fs) or coroutines.iscoroutine(fs):
-        raise TypeError(f"expect a list of futures, not {type(fs).__name__}")
+        raise TypeError(f"expect an iterable of futures, not {type(fs).__name__}")
 
     from .queues import Queue  # Import here to avoid circular import problem.
     done = Queue(loop=loop)