bpo-32154: Remove asyncio.selectors (#4605)

* Remove asyncio.selectors and asyncio._overlapped symbols from the
  namespace of the asyncio module
* Replace "from asyncio import selectors" with "import selectors"
* Replace "from asyncio import _overlapped" with "import _overlapped"

asyncio.selectors was added to support Python 3.3, which doesn't have
selectors in its standard library, and Python 3.4 in the same code
base. Same rationale for asyncio._overlapped. Python 3.3 reached its
end of life, and asyncio is no more maintained as a third party
module on PyPI.

1 files changed, 0 insertions, 15 deletions

diff --git a/Lib/asyncio/__init__.py b/Lib/asyncio/__init__.py
index 011466b3e0d..1ee1b2516d4 100644
--- a/Lib/asyncio/__init__.py
+++ b/Lib/asyncio/__init__.py
@@ -2,21 +2,6 @@
 
 import sys
 
-# The selectors module is in the stdlib in Python 3.4 but not in 3.3.
-# Do this first, so the other submodules can use "from . import selectors".
-# Prefer asyncio/selectors.py over the stdlib one, as ours may be newer.
-try:
-    from . import selectors
-except ImportError:
-    import selectors  # Will also be exported.
-
-if sys.platform == 'win32':
-    # Similar thing for _overlapped.
-    try:
-        from . import _overlapped
-    except ImportError:
-        import _overlapped  # Will also be exported.
-
 # This relies on each of the submodules having an __all__ variable.
 from .base_events import *
 from .coroutines import *