python / cpython

…afety. (GH-18786)

`list(sys.modules.items())` was apparently not immune to "dictionary
changed size during iteration" errors.

Tested internally using an integration test that has run into this a couple of times in the past two years.  With this patch applied, the test is no longer flaky.

GH-18784)

GH-16959)" (GH-18767)

This reverts commit e471e72.

The mode will be removed from Python 3.10.

Split long build_extensions() method into sub-methods.

Fix also a typo in Popen.wait(): replace sts with status.

The AST "Suite" node is no longer used and it can be removed from the ASDL definition and related structures (compiler, visitors, ...).

Co-Authored-By: Victor Stinner <vstinner@python.org>
Co-authored-by: Brett Cannon <54418+brettcannon@users.noreply.github.com>
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>

…8675)

Reimplement distutils.spawn.spawn() function with the subprocess
module.

setup.py now uses a basic implementation of the subprocess module if
the subprocess module is not available: before required C extension
modules are built.

Add a section in What's New In Python 3.9 to strongly advice to check
for DeprecationWarning in your Python projects.

Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>

…recation warning (GH-13195)

…enames (GH-18720)

When filesystem encoding cannot encode the Unicode string used for a filename
continue testing with the next example.

Automerge-Triggered-By: @pablogsal

…sions are activated (GH-18705)

Automerge-Triggered-By: @brettcannon

…dows (GH-18724)

…rse and tp_clear (GH-18749)

Objects do not own weak references to them directly through the __weakref__ list so these
do not need to be traversed by the GC.

  - Threads created by PyGILState_Ensure() could have a duplicate tstate->id.

Allow ast.unparse to detect docstrings in functions, modules and classes and produce
nicely formatted unparsed output for said docstrings.

Co-Authored-By: Pablo Galindo <Pablogsal@gmail.com>

* Add _PyWarnings_InitState() which only initializes the _warnings
  module state (tstate->interp->warnings) without creating a module
  object
* Py_InitializeFromConfig() now calls _PyWarnings_InitState() instead
  of _PyWarnings_Init()
* Rename also private functions of _warnings.c to avoid confusion
  between the public C API and the private C API.

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>

Automerge-Triggered-By: @zooba

…H-18684)

…h exception raised. (GH-18656)

…-17666)

Open issue in the BPO indicated a desire to make the implementation of
codecs.open() at parity with io.open(), which implements a try/except to
assure file stream gets closed before an exception is raised.

…18275)

… documentation (GH-17812)

Adapted from https://greentreesnakes.readthedocs.io

Co-authored-by: Karthikeyan Singaravelan <tir.karthi@gmail.com>
Co-authored-by: Carol Willing <carolcode@willingconsulting.com>