Show sys.version when -V option is supplied twice.
The with-statement now checks for __enter__ before it checks for __exit__. This gives less confusing error messages when both methods are missing. Patch by Jonathan Ellington.
Fix the set_inheritable() file descriptor method on platforms that do not have the ioctl FIOCLEX and FIONCLEX commands.
Fix not getting the locale's charset upon initializing the interpreter, on platforms that do not have langinfo.
Fixed crash in Py_DecodeLocale() in debug build on Mac OS X when decode astral characters. Patch by Xiang Zhang.
Extra slash no longer added to sys.path components in case of empty compile-time PYTHONPATH components.
Improve speed of the STORE_DEREF opcode by 40%.
PyDict_SetDefault didn't combine split table when needed. Patch by Xiang Zhang.
Change PendingDeprecationWarning -> DeprecationWarning. As it was agreed in the issue, __aiter__ returning an awaitable should result in PendingDeprecationWarning in 3.5 and in DeprecationWarning in 3.6.
Fix a refleak in code that raises DeprecationWarning.
Fix asynchronous generators aclose() and athrow() to handle StopAsyncIteration propagation properly.
Restored the __reduce__() methods of datetime objects.
Regular expression patterns, _sre.SRE_Pattern objects created by re.compile(), become comparable (only x==y and x!=y operators). This change should fix the issue #18383: don't duplicate warning filters when the warnings module is reloaded (thing usually only done in unit tests).
The subprocess.Popen.wait method's undocumented endtime parameter now raises a DeprecationWarning.
In ctypes, prevent a crash calling the from_buffer() and from_buffer_copy() methods on abstract classes like Array.
Makes Path.resolve() succeed on paths that do not exist. Patch by Vajrasky Kok
Fixed possible DoS and arbitrary code execution when handle plural form selections in the gettext module. The expression parser now supports exact syntax supported by GNU gettext.
Fixed possible crash in _io.TextIOWrapper deallocator when the garbage collector is invoked in other thread. Based on patch by Sebastian Cufre.
Optimize loop.call_soon.
Fix get_event_loop() return the current loop if called from coroutines/callbacks.
Fix asyncio.isfuture() to support unittest.Mock.
Fix refleak in _asyncio.Future.__iter__().throw.
Fix inspect.isawaitable to always return bool Patch by Justin Mayfield.
Make loop methods reject socket kinds they do not support.
Fix a refleak in functools.lru_cache.
Fix asyncio.iscoroutinefunction to handle Mock objects.
Fix create_unix_server to support Path-like objects (PEP 519).
Add collections.abc.AsyncGenerator.
Documented command-line interface of zipfile.
Now test.support.rmtree is able to remove unwritable or unreadable directories.
Various caches now are cleared before running every test file.
Fix out-of-tree building on AIX. Patch by Tristan Carel and Michael Haubenwallner.
Rename --with-optimiations to --enable-optimizations.
Prevent missing 'getentropy' declaration warning on macOS. Patch by Gareth Rees.