gh-127949: remove asyncio policy system

Doc/deprecations/pending-removal-in-3.16.rst

@@ -23,30 +23,6 @@ Pending removal in Python 3.16
     use :func:`inspect.iscoroutinefunction` instead.
     (Contributed by Jiahao Li and Kumar Aditya in :gh:`122875`.)
 
-  * :mod:`asyncio` policy system is deprecated and will be removed in Python 3.16.
-    In particular, the following classes and functions are deprecated:
-
-    * :class:`asyncio.AbstractEventLoopPolicy`
-    * :class:`asyncio.DefaultEventLoopPolicy`
-    * :class:`asyncio.WindowsSelectorEventLoopPolicy`
-    * :class:`asyncio.WindowsProactorEventLoopPolicy`
-    * :func:`asyncio.get_event_loop_policy`
-    * :func:`asyncio.set_event_loop_policy`
-
-    Users should use :func:`asyncio.run` or :class:`asyncio.Runner` with
-    *loop_factory* to use the desired event loop implementation.
-
-    For example, to use :class:`asyncio.SelectorEventLoop` on Windows::
-
-      import asyncio
-
-      async def main():
-          ...
-
-      asyncio.run(main(), loop_factory=asyncio.SelectorEventLoop)
-
-    (Contributed by Kumar Aditya in :gh:`127949`.)
-
 * :mod:`builtins`:
 
   * Bitwise inversion on boolean types, ``~True`` or ``~False``

Doc/library/asyncio-eventloop.rst

@@ -48,10 +48,10 @@ an event loop:
    running event loop.
 
    If there is no running event loop set, the function will return
-   the result of the ``get_event_loop_policy().get_event_loop()`` call.
+   the loop set by :func:`set_event_loop`, or raise a :exc:`RuntimeError`
+   if no loop has been set.
 
-   Because this function has rather complex behavior (especially
-   when custom event loop policies are in use), using the
+   Because this function has rather complex behavior, using the
    :func:`get_running_loop` function is preferred to :func:`get_event_loop`
    in coroutines and callbacks.
 
@@ -62,13 +62,6 @@ an event loop:
    .. versionchanged:: 3.14
       Raises a :exc:`RuntimeError` if there is no current event loop.
 
-   .. note::
-
-      The :mod:`!asyncio` policy system is deprecated and will be removed
-      in Python 3.16; from there on, this function will return the current
-      running event loop if present else it will return the
-      loop set by :func:`set_event_loop`.
-
 .. function:: set_event_loop(loop)
 
    Set *loop* as the current event loop for the current OS thread.
@@ -77,10 +70,6 @@ an event loop:
 
    Create and return a new event loop object.
 
-Note that the behaviour of :func:`get_event_loop`, :func:`set_event_loop`,
-and :func:`new_event_loop` functions can be altered by
-:ref:`setting a custom event loop policy <asyncio-policies>`.
-
 
 .. rubric:: Contents
 

Doc/library/asyncio-llapi-index.rst

@@ -497,27 +497,3 @@ Protocol classes can implement the following **callback methods**:
       - Called when the child process has exited. It can be called before
         :meth:`~SubprocessProtocol.pipe_data_received` and
         :meth:`~SubprocessProtocol.pipe_connection_lost` methods.
-
-
-Event Loop Policies
-===================
-
-Policies is a low-level mechanism to alter the behavior of
-functions like :func:`asyncio.get_event_loop`.  See also
-the main :ref:`policies section <asyncio-policies>` for more
-details.
-
-
-.. rubric:: Accessing Policies
-.. list-table::
-    :widths: 50 50
-    :class: full-width-table
-
-    * - :meth:`asyncio.get_event_loop_policy`
-      - Return the current process-wide policy.
-
-    * - :meth:`asyncio.set_event_loop_policy`
-      - Set a new process-wide policy.
-
-    * - :class:`AbstractEventLoopPolicy`
-      - Base class for policy objects.

Doc/library/asyncio-runner.rst

@@ -43,9 +43,7 @@ Running an asyncio Program
    otherwise :func:`asyncio.new_event_loop` is used. The loop is closed at the end.
    This function should be used as a main entry point for asyncio programs,
    and should ideally only be called once. It is recommended to use
-   *loop_factory* to configure the event loop instead of policies.
-   Passing :class:`asyncio.EventLoop` allows running asyncio without the
-   policy system.
+   *loop_factory* to configure the event loop.
 
    The executor is given a timeout duration of 5 minutes to shutdown.
    If the executor hasn't finished within that duration, a warning is
@@ -76,12 +74,6 @@ Running an asyncio Program
 
       *coro* can be any awaitable object.
 
-   .. note::
-
-      The :mod:`!asyncio` policy system is deprecated and will be removed
-      in Python 3.16; from there on, an explicit *loop_factory* is needed
-      to configure the event loop.
-
 
 Runner context manager
 ======================

Doc/library/asyncio.rst

@@ -117,7 +117,6 @@ for full functionality and the latest features.
    asyncio-eventloop.rst
    asyncio-future.rst
    asyncio-protocol.rst
-   asyncio-policy.rst
    asyncio-platforms.rst
    asyncio-extending.rst
 

Doc/whatsnew/3.14.rst

@@ -2628,12 +2628,12 @@ New deprecations
     and will be removed in Python 3.16.
     In particular, the following classes and functions are deprecated:
 
-    * :class:`asyncio.AbstractEventLoopPolicy`
-    * :class:`asyncio.DefaultEventLoopPolicy`
-    * :class:`asyncio.WindowsSelectorEventLoopPolicy`
-    * :class:`asyncio.WindowsProactorEventLoopPolicy`
-    * :func:`asyncio.get_event_loop_policy`
-    * :func:`asyncio.set_event_loop_policy`
+    * :class:`!asyncio.AbstractEventLoopPolicy`
+    * :class:`!asyncio.DefaultEventLoopPolicy`
+    * :class:`!asyncio.WindowsSelectorEventLoopPolicy`
+    * :class:`!asyncio.WindowsProactorEventLoopPolicy`
+    * :func:`!asyncio.get_event_loop_policy`
+    * :func:`!asyncio.set_event_loop_policy`
 
     Users should use :func:`asyncio.run` or :class:`asyncio.Runner` with
     the *loop_factory* argument to use the desired event loop implementation.

Doc/whatsnew/3.16.rst

@@ -121,6 +121,17 @@ asyncio
   which has been deprecated since Python 3.14.
   Use :func:`inspect.iscoroutinefunction` instead.
 
+* The event loop policy system, including the
+  :class:`!asyncio.AbstractEventLoopPolicy`,
+  :class:`!asyncio.DefaultEventLoopPolicy`,
+  :class:`!asyncio.WindowsSelectorEventLoopPolicy` and
+  :class:`!asyncio.WindowsProactorEventLoopPolicy` classes and the
+  :func:`!asyncio.get_event_loop_policy` and
+  :func:`!asyncio.set_event_loop_policy` functions,
+  which have been deprecated since Python 3.14.
+  Use :func:`asyncio.run` or :class:`asyncio.Runner` with a custom
+  *loop_factory* instead.
+
 functools
 ---------
 

Lib/asyncio/__init__.py

@@ -47,28 +47,3 @@
 else:
     from .unix_events import *  # pragma: no cover
     __all__ += unix_events.__all__
-
-def __getattr__(name: str):
-    import warnings
-
-    match name:
-        case "AbstractEventLoopPolicy":
-            warnings._deprecated(f"asyncio.{name}", remove=(3, 16))
-            return events._AbstractEventLoopPolicy
-        case "DefaultEventLoopPolicy":
-            warnings._deprecated(f"asyncio.{name}", remove=(3, 16))
-            if sys.platform == 'win32':
-                return windows_events._DefaultEventLoopPolicy
-            return unix_events._DefaultEventLoopPolicy
-        case "WindowsSelectorEventLoopPolicy":
-            if sys.platform == 'win32':
-                warnings._deprecated(f"asyncio.{name}", remove=(3, 16))
-                return windows_events._WindowsSelectorEventLoopPolicy
-            # Else fall through to the AttributeError below.
-        case "WindowsProactorEventLoopPolicy":
-            if sys.platform == 'win32':
-                warnings._deprecated(f"asyncio.{name}", remove=(3, 16))
-                return windows_events._WindowsProactorEventLoopPolicy
-            # Else fall through to the AttributeError below.
-
-    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")