https://bugs.python.org/issue36374

_PyCoreConfig_ReadFromArgv() now reuses the code parsing command line
options from preconfig.c.

https://bugs.python.org/issue23984

Don't override parameters which are already set by the user.

* Add _PyRuntime.pre_initialized: set to 1 when Python
  is pre-initialized
* Add _Py_PreInitialize() and _Py_PreInitializeFromPreConfig().
* _PyCoreConfig_Read() now calls  _Py_PreInitialize().
* Move _PyPreConfig_GetGlobalConfig() and
  _PyCoreConfig_GetGlobalConfig() calls from main.c to preconfig.c
  and coreconfig.c.

https://bugs.python.org/issue36362

No longer limit repr(structseq) to 512 bytes. Use _PyUnicodeWriter
for better performance and to write directly Unicode rather than
encoding repr() value to UTF-8 and then decoding from UTF-8.

Calling _PyRuntime_Initialize() after _PyRuntime_Finalize() now re-initializes
_PyRuntime structure. Previously, _PyRuntime_Initialize() did
nothing in that case.

https://bugs.python.org/issue36324

* _PyPathConfig_ComputeSysPath0() now returns 0 if argv is empty.
* Cleanup also _PyPathConfig_ComputeSysPath0() code: move variables
  definitions closer to where they are used.

At Python initialization, the current directory is no longer
prepended to sys.path if it has been removed.

Rename _PyPathConfig_ComputeArgv0() to
_PyPathConfig_ComputeSysPath0() to avoid confusion between argv[0]
and sys.path[0].

Ensure that _PyRuntime_Finalize() is always call. This change fix a
few memory leaks when running "python3 -V".

When Python is compiled with Valgrind support, release Unicode
interned strings at exit in _PyUnicode_Fini().

* Rename _Py_ReleaseInternedUnicodeStrings() to
  unicode_release_interned() and make it private.
* unicode_release_interned() is now called from _PyUnicode_Fini():
  it must be called with a running Python thread state for TRASHCAN,
  it cannot be called from pymain_free().
* Don't display statistics on interned strings at exit anymore

_PyEval_FiniThreads() now free the pending lock.

Modules/_sqlite/cursor.c uses "y#" format.
It didn't declare PY_SSIZE_T_CLEAN, but the argument is Py_ssize_t already.

_PyPreConfig_Read() now free 'old_old' at exit.

* Use Py_ARRAY_LENGTH() rather than hardcoded MAXPATHLEN in getpath.c.
* Pass string length to functions modifying strings.

Python initialization now fails if decoding pybuilddir.txt
configuration file fails at startup.

_PyPathConfig_Calculate() now reports memory allocation failure and
decoding error on decoding pybuilddir.txt content from
UTF-8/surrogateescape.

Replace Py_FatalError() with _PyInitError to let the caller handle
the fatal error.

bpo-36301, bpo-36333:

* Fix memory allocator used by _PyPathConfig_ClearGlobal():
  force the default allocator.
* _PyPreConfig_ReadFromArgv(): free init_ctype_locale memory.
* pymain_main(): call pymain_free() on init error
Co-Authored-By: Stéphane Wirtel <stephane@wirtel.be>

Also,  deprecate the *_field_types* attributes which duplicated the information in *\__annotations__*.


https://bugs.python.org/issue36320

The last parameter of _Py_wreadlink(), _Py_wrealpath() and
_Py_wgetcwd() is a length, not a size: number of characters including
the trailing NUL character.

Enhance also documentation of error conditions.

The test test_customize_compiler() now mocks all sysconfig variables
and all environment variables used by customize_compiler().

* bpo-36329: Declare the version of Python to use for Tools/scripts/serve.py

* Add the blurb entry