Issue 25002: Deprecate asyncore/asynchat. Patch by Mariatta.

Doc/library/asynchat.rst

@@ -9,6 +9,9 @@
 
 **Source code:** :source:`Lib/asynchat.py`
 
+.. deprecated:: 3.6
+   Please use :mod:`asyncio` instead.
+
 --------------
 
 .. note::

Doc/library/asyncore.rst

@@ -12,6 +12,9 @@
 
 **Source code:** :source:`Lib/asyncore.py`
 
+.. deprecated:: 3.6
+   Please use :mod:`asyncio` instead.
+
 --------------
 
 .. note::

Lib/asynchat.py

@@ -46,8 +46,13 @@ method) up to the terminator, and then control will be returned to
 you - by calling your self.found_terminator() method.
 """
 import asyncore
+import warnings
+
 from collections import deque
 
+warnings.warn(
+    'asynchat module is deprecated in 3.6. Use asyncio instead.',
+    PendingDeprecationWarning, stacklevel=2)
 
 class async_chat(asyncore.dispatcher):
     """This is an abstract class.  You must derive from this class, and add

Lib/asyncore.py

@@ -60,6 +60,10 @@ from errno import EALREADY, EINPROGRESS, EWOULDBLOCK, ECONNRESET, EINVAL, \
 _DISCONNECTED = frozenset({ECONNRESET, ENOTCONN, ESHUTDOWN, ECONNABORTED, EPIPE,
                            EBADF})
 
+warnings.warn(
+    'asyncore module is deprecated in 3.6. Use asyncio instead.',
+    PendingDeprecationWarning, stacklevel=2)
+
 try:
     socket_map
 except NameError: