bpo-34572: change _pickle unpickling to use import rather than retrieving from sys.modules (GH-9047)

Fix C implementation of pickle.loads to use importlib's locking mechanisms, and thereby avoid using partially-loaded modules.

Need to reset capturing groups between two SRE(match) callings in loops, this fixes wrong capturing groups in rare cases.

Also add a missing index in re.rst.

The wrong NEWS snippet was inadvertently included in
GH-11500, this switches to the correct one.


https://bugs.python.org/issue35704

https://bugs.python.org/issue35704

bpo-35942: Improve the error message if __fspath__ returns invalid types in path_converter (GH-11831)

The error message emitted when returning invalid types from __fspath__ in interfaces that allow passing PathLike objects has been improved and now it does explain the origin of the error.

Not using `__class_getitem__()` fallback if there is a non-subcriptable metaclass was caused by a certain asymmetry between how `PySequenceMethods` and `PyMappingMethods` are used in `PyObject_GetItem`. This PR removes this asymmetry. No tests failed, so I assume it was not intentional.

Fix  Modules/_testmultiphase.c so that it exits with non-zero status on AIX just as other systems do (non zero exit status, e.g. as result of a segmentation fault) when a NULL pointer is accessed for data.


https://bugs.python.org/issue34720

It makes the existing smaller test more readable and robust at the same time.

The execution of a shell in interactive mode from CI and buildbot test automation wasn't working out.  What would work locally in our terminals would only work within a fraction of automation systems.  The integration test was a nice to have.  painful.  deleting. :)

* bpo-1054041: Exit properly by a signal after a ^C.

An uncaught KeyboardInterrupt exception means the user pressed ^C and
our code did not handle it.  Programs that install SIGINT handlers are
supposed to reraise the SIGINT signal to the SIG_DFL handler in order
to exit in a manner that their calling process can detect that they
died due to a Ctrl-C.  https://www.cons.org/cracauer/sigint.html

After this change on POSIX systems

 while true; do python -c 'import time; time.sleep(23)'; done

can be stopped via a simple Ctrl-C instead of the shell infinitely
restarting a new python process.

What to do on Windows, or if anything needs to be done there has not
yet been determined.  That belongs in its own PR.

TODO(gpshead): A unittest for this behavior is still needed.

* Do the unhandled ^C check after pymain_free.

* Return STATUS_CONTROL_C_EXIT on Windows.

* Fix ifdef around unistd.h include.

* 📜🤖 Added by blurb_it.

* Add STATUS_CTRL_C_EXIT to the os module on Windows

* Add unittests.

* Don't send CTRL_C_EVENT in the Windows test.

It was causing CI systems to bail out of the entire test suite.

See https://dev.azure.com/Python/cpython/_build/results?buildId=37980
for example.

* Correct posix test (fail on macOS?) check.

* STATUS_CONTROL_C_EXIT must be unsigned.

* Improve the error message.

* test typo :)

* Skip if the bash version is too old.

...and rename the windows test to reflect what it does.

* min bash version is 4.4, detect no bash.

* restore a blank line i didn't mean to delete.

* PyErr_Occurred() before the Py_DECREF(co);

* Don't add os.STATUS_CONTROL_C_EXIT as a constant.

* Update the Windows test comment.

* Refactor common logic into a run_eval_code_obj fn.

https://bugs.python.org/issue35884

https://bugs.python.org/issue33234

https://bugs.python.org/issue32492

https://bugs.python.org/issue33089

https://bugs.python.org/issue36007

https://bugs.python.org/issue35984

Previously, `debug print(` would cause the interpreter to exit on a SyntaxError whereas `print(` would properly display the error and return to the pdb prompt.

This patch fixes this by pre-compiling the code before passing it to `Pdb.run`.


https://bugs.python.org/issue35931

Based on reviewer feedback from Allen Downey, convert ``lambda`` to ``def``.

The earliest version that `typing.NoReturn` appears in is [3.5.4rc1](https://docs.python.org/3/whatsnew/changelog.html#python-3-5-4-release-candidate-1)

https://bugs.python.org/issue36006

Add credit for the cert parser vulnerability. Mention also Cisco
TALOS-2018-0758 identifier.

https://bugs.python.org/issue35994

Documentation of sys.stdin/out/err update to reflect change in 3.6 on Windows to use UTF-8.

Wording by Eryk Sun and Paul Moore.



https://bugs.python.org/issue30410

bpo-35633: test_lockf() fails with "PermissionError: [Errno 13] Permission denied" on AIX (GH-11424)



[bpo-35633](https://bugs.python.org/issue35633): Fix a test regression introduced with [bpo-35189](https://bugs.python.org/issue35189) (PEP 475: fnctl functions are not retried if interrupted (EINTR)).

Not only a blocking IO error needs to be ignored - permission errors also need to be ignored.

p.s. - iirc as a "test" only correction a NEWS item is not required. If this is not correct - just mention, and I'll add a NEWS blurb.


https://bugs.python.org/issue35633

This change adds the necessary items to the build projects to avoid erroring out right at the start. It does not add _support_ for targeting Windows on ARM32, but is a necessary prerequisite for adding it.

Fix a crash in slice_richcompare(): use strong references rather than
stolen references for the two temporary internal tuples.

The crash (or assertion error) occurred if a garbage collection
occurred during slice_richcompare(), especially while calling
PyObject_RichCompare(t1, t2, op).

Minor code clean-up.

Make test_imap4_host_default_value independent on whether the 
local IMAP server is running.

bpo-35972: _xxsubinterpreters: Fix potential integer truncation on 32-bit in channel_send() (gh-11822)