[issue24692] types.coroutines() idempotence documentation
New submission from Antoine Pietri: In the new types.coroutines() documentation, it is not clearly stated whether this function is idempotent or not: what happens when it is called on a function that is already a native coroutine? ---------- assignee: docs@python components: Documentation messages: 247184 nosy: docs@python, seirl priority: normal severity: normal status: open title: types.coroutines() idempotence documentation versions: Python 3.5 _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue24692> _______________________________________
Roundup Robot added the comment: New changeset 636ce05ea8f6 by Yury Selivanov in branch '3.5': Issue #24692: Add more tests for types.coroutine https://hg.python.org/cpython/rev/636ce05ea8f6 New changeset 3f3e398bcd3e by Yury Selivanov in branch 'default': Merge 3.5 (Issue #24692) https://hg.python.org/cpython/rev/3f3e398bcd3e ---------- nosy: +python-dev _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue24692> _______________________________________
Changes by Yury Selivanov <yselivanov@gmail.com>: ---------- nosy: +vadmium _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue24692> _______________________________________
Martin Panter added the comment: Going by Yury’s tests and implementation, I think it is intended that: * An “async def” coroutine factory function is accepted and passed through unmodified * An generator–coroutine factory function that has already been transformed is also accepted * If a wrapped function (not a normal coroutine nor generator factory) returns a coroutine instance (e.g. if the function was already decorated), the return value is never wrapped a second time I will have a go at writing this up. ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue24692> _______________________________________
Martin Panter added the comment: Let me know if this patch works for you. ---------- keywords: +patch stage: -> patch review versions: +Python 3.6 Added file: http://bugs.python.org/file40050/coro-idempotent.patch _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue24692> _______________________________________
Antoine Pietri added the comment: Lgtm! ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue24692> _______________________________________
Stefan Behnel added the comment: Note that the expected usage is not as a function but as a decorator. That should be stated in the docs as well. IMHO, users should only do two things with whatever the result is: either use it as a Generator (as before), or pass it as an argument to "await". Everything else is best considered implementation details. Well, except for the case of passing a coroutine, which will obviously just be passed through (and that answers the original question). ---------- nosy: +scoder _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue24692> _______________________________________
Martin Panter added the comment: I think you are right that it would be typically used as a decorator. Patch v2 changes it to be defined as a decorator. Not sure what the second part of your comment is referring to. The existing text about lack of __await__() maybe? You still have to have something (such as “asyncio”) drive the top-level coroutine. So that is a third thing users have to do with them. Passing a coroutine to “await” does not magically make it go, it just becomes a subordinate of the outer coroutine. ---------- Added file: http://bugs.python.org/file40092/coro-idempotent.v2.patch _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue24692> _______________________________________
Yury Selivanov added the comment: Is this still something that we need to address? I think that the current types.coroutine docs are pretty accurate and don't see where the proposed patch really improves them. ---------- nosy: +yselivanov _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue24692> _______________________________________
Antoine Pietri added the comment: I checked, the current doc gives a good explanation. I'm closing the issue. ---------- stage: patch review -> resolved status: open -> closed _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue24692> _______________________________________
participants (5)
-
Antoine Pietri -
Martin Panter
-
Roundup Robot
-
Stefan Behnel
-
Yury Selivanov