bpo-43216: Remove @asyncio.coroutine (GH-26369)

Remove the @asyncio.coroutine decorator
enabling legacy generator-based coroutines to be compatible with async/await
code; remove asyncio.coroutines.CoroWrapper used for wrapping
legacy coroutine objects in the debug mode.

The decorator has been deprecated
since Python 3.8 and the removal was initially scheduled for Python 3.10.

Doc/library/asyncio-task.rst

@@ -148,9 +148,6 @@ other coroutines::
    * a *coroutine object*: an object returned by calling a
      *coroutine function*.
 
-asyncio also supports legacy :ref:`generator-based
-<asyncio_generator_based_coro>` coroutines.
-
 
 .. rubric:: Tasks
 
@@ -1042,60 +1039,3 @@ Task Object
       in the :func:`repr` output of a task object.
 
       .. versionadded:: 3.8
-
-
-.. _asyncio_generator_based_coro:
-
-Generator-based Coroutines
-==========================
-
-.. note::
-
-   Support for generator-based coroutines is **deprecated** and
-   is scheduled for removal in Python 3.10.
-
-Generator-based coroutines predate async/await syntax.  They are
-Python generators that use ``yield from`` expressions to await
-on Futures and other coroutines.
-
-Generator-based coroutines should be decorated with
-:func:`@asyncio.coroutine <asyncio.coroutine>`, although this is not
-enforced.
-
-
-.. decorator:: coroutine
-
-    Decorator to mark generator-based coroutines.
-
-    This decorator enables legacy generator-based coroutines to be
-    compatible with async/await code::
-
-        @asyncio.coroutine
-        def old_style_coroutine():
-            yield from asyncio.sleep(1)
-
-        async def main():
-            await old_style_coroutine()
-
-    This decorator should not be used for :keyword:`async def`
-    coroutines.
-
-    .. deprecated-removed:: 3.8 3.10
-
-       Use :keyword:`async def` instead.
-
-.. function:: iscoroutine(obj)
-
-   Return ``True`` if *obj* is a :ref:`coroutine object <coroutine>`.
-
-   This method is different from :func:`inspect.iscoroutine` because
-   it returns ``True`` for generator-based coroutines.
-
-.. function:: iscoroutinefunction(func)
-
-   Return ``True`` if *func* is a :ref:`coroutine function
-   <coroutine>`.
-
-   This method is different from :func:`inspect.iscoroutinefunction`
-   because it returns ``True`` for generator-based coroutine functions
-   decorated with :func:`@coroutine <coroutine>`.

Doc/library/collections.abc.rst

@@ -198,7 +198,7 @@ ABC                        Inherits from          Abstract Methods        Mixin
 
    .. note::
       In CPython, generator-based coroutines (generators decorated with
-      :func:`types.coroutine` or :func:`asyncio.coroutine`) are
+      :func:`types.coroutine`) are
       *awaitables*, even though they do not have an :meth:`__await__` method.
       Using ``isinstance(gencoro, Awaitable)`` for them will return ``False``.
       Use :func:`inspect.isawaitable` to detect them.
@@ -216,7 +216,7 @@ ABC                        Inherits from          Abstract Methods        Mixin
 
    .. note::
       In CPython, generator-based coroutines (generators decorated with
-      :func:`types.coroutine` or :func:`asyncio.coroutine`) are
+      :func:`types.coroutine`) are
       *awaitables*, even though they do not have an :meth:`__await__` method.
       Using ``isinstance(gencoro, Coroutine)`` for them will return ``False``.
       Use :func:`inspect.isawaitable` to detect them.

Doc/reference/datamodel.rst

@@ -2714,7 +2714,7 @@ are awaitable.
 .. note::
 
    The :term:`generator iterator` objects returned from generators
-   decorated with :func:`types.coroutine` or :func:`asyncio.coroutine`
+   decorated with :func:`types.coroutine`
    are also awaitable, but they do not implement :meth:`__await__`.
 
 .. method:: object.__await__(self)

Doc/whatsnew/3.11.rst

@@ -171,7 +171,15 @@ Deprecated
 Removed
 =======
 
+* The :func:`@asyncio.coroutine <asyncio.coroutine>` :term:`decorator` enabling
+  legacy generator-based coroutines to be compatible with async/await code.
+  The function has been deprecated since Python 3.8 and the removal was
+  initially scheduled for Python 3.10. Use :keyword:`async def` instead.
+  (Contributed by Illia Volochii in :issue:`43216`.)
 
+* :class:`asyncio.coroutines.CoroWrapper` used for wrapping legacy
+  generator-based coroutine objects in the debug mode.
+  (Contributed by Illia Volochii in :issue:`43216`.)
 
 Porting to Python 3.11
 ======================