See [PEP 597](https://www.python.org/dev/peps/pep-0597/).
* Add `-X warn_default_encoding` and `PYTHONWARNDEFAULTENCODING`.
* Add EncodingWarning
* Add io.text_encoding()
* open(), TextIOWrapper() emits EncodingWarning when encoding is omitted and warn_default_encoding is enabled.
* _pyio.TextIOWrapper() uses UTF-8 as fallback default encoding used when failed to import locale module. (used during building Python)
* bz2, configparser, gzip, lzma, pathlib, tempfile modules use io.text_encoding().
* What's new entry
Remove the pyarena.h header file with functions:
* PyArena_New()
* PyArena_Free()
* PyArena_Malloc()
* PyArena_AddPyObject()
These functions were undocumented, excluded from the limited C API,
and were only used internally by the compiler.
Add pycore_pyarena.h header. Rename functions:
* PyArena_New() => _PyArena_New()
* PyArena_Free() => _PyArena_Free()
* PyArena_Malloc() => _PyArena_Malloc()
* PyArena_AddPyObject() => _PyArena_AddPyObject()
Remove parser functions using the "struct _mod" type, because the
AST C API was removed:
* PyParser_ASTFromFile()
* PyParser_ASTFromFileObject()
* PyParser_ASTFromFilename()
* PyParser_ASTFromString()
* PyParser_ASTFromStringObject()
These functions were undocumented and excluded from the limited C
API.
Add pycore_parser.h internal header file. Rename functions:
* PyParser_ASTFromFileObject() => _PyParser_ASTFromFile()
* PyParser_ASTFromStringObject() => _PyParser_ASTFromString()
These functions are no longer exported (replace PyAPI_FUNC() with
extern).
Remove also _PyPegen_run_parser_from_file() function. Update
test_peg_generator to use _PyPegen_run_parser_from_file_pointer()
instead.
Remove the compiler functions using "struct _mod" type, because the
public AST C API was removed:
* PyAST_Compile()
* PyAST_CompileEx()
* PyAST_CompileObject()
* PyFuture_FromAST()
* PyFuture_FromASTObject()
These functions were undocumented and excluded from the limited C API.
Rename functions:
* PyAST_CompileObject() => _PyAST_Compile()
* PyFuture_FromASTObject() => _PyFuture_FromAST()
Moreover, _PyFuture_FromAST() is no longer exported (replace
PyAPI_FUNC() with extern). _PyAST_Compile() remains exported for
test_peg_generator.
Remove also compatibility functions:
* PyAST_Compile()
* PyAST_CompileEx()
* PyFuture_FromAST()
These functions were undocumented and excluded from the limited C
API.
Most names defined by these header files were not prefixed by "Py"
and so could create names conflicts. For example, Python-ast.h
defined a "Yield" macro which was conflict with the "Yield" name used
by the Windows <winbase.h> header.
Use the Python ast module instead.
* Move Include/asdl.h to Include/internal/pycore_asdl.h.
* Move Include/Python-ast.h to Include/internal/pycore_ast.h.
* Remove ast.h header file.
* pycore_symtable.h no longer includes Python-ast.h.
Rename Include/symtable.h to to Include/internal/pycore_symtable.h,
don't export symbols anymore (replace PyAPI_FUNC and PyAPI_DATA with
extern) and rename functions:
* PyST_GetScope() to _PyST_GetScope()
* PySymtable_BuildObject() to _PySymtable_Build()
* PySymtable_Free() to _PySymtable_Free()
Remove PySymtable_Build(), Py_SymtableString() and
Py_SymtableStringObject() functions.
The Py_SymtableString() function was part the stable ABI by mistake
but it could not be used, since the symtable.h header file was
excluded from the limited C API.
The Python symtable module remains available and is unchanged.
Remove the PyAST_Validate() function. It is no longer possible to
build a AST object (mod_ty type) with the public C API. The function
was already excluded from the limited C API (PEP 384).
Rename PyAST_Validate() function to _PyAST_Validate(), move it to the
internal C API, and don't export it anymore (replace PyAPI_FUNC with
extern).
The function was added in bpo-12575 by
the commit 832bfe2ebd.
* Remove an assertion which required CO_NEWLOCALS and CO_OPTIMIZED
code flags. It is ok to call this function on a code with these
flags set.
* Fix reference counting on builtins: remove Py_DECREF().
Fix regression introduced in the
commit 46496f9d12.
Add also a comment to document that _PyEval_BuiltinsFromGlobals()
returns a borrowed reference.
test_peg_generator now defines _Py_TEST_PEGEN macro when building C
code to not call PyAST_Validate() in Parser/pegen.c. Moreover, it
defines Py_BUILD_CORE_MODULE macro to get access to the internal
C API.
Remove "global_ast_state" from Python-ast.c when it's built by
test_peg_generator: always get the AST state from the current interpreter.
Move _PyAST_GetDocString() and _PyAST_ExprAsUnicode() functions the
internal C API: from Include/ast.h to a new
Include/internal/pycore_ast.h header file. Don't export these
functions anymore: replace PyAPI_FUNC() with extern.
Remove also unused includes.
Python no longer fails at startup with a fatal error if a command
line argument contains an invalid Unicode character.
The Py_DecodeLocale() function now escapes byte sequences which would
be decoded as Unicode characters outside the [U+0000; U+10ffff]
range.
Use MAX_UNICODE constant in unicodeobject.c.
* bpo-43497: Emit SyntaxWarnings for assertions with tuple constants.
Add a test that shows that a tuple constant (a tuple, where all of its
members are also compile-time constants) produces a SyntaxWarning. Then
fix this failure.
* Make SyntaxWarnings also work when "optimized".
* Split tests for SyntaxWarning to SyntaxError conversion
SyntaxWarnings emitted by the compiler when configured to be errors are
actually raised as SyntaxError exceptions.
Move these tests into their own method and add a test to ensure they are
raised. Previously we only tested that they were not raised for a
"valid" assertion statement.
At Python startup, call _PyGILState_Init() before
PyInterpreterState_New() which calls _PyThreadState_GET(). When
Python is built using --with-experimental-isolated-subinterpreters,
_PyThreadState_GET() uses autoTSSkey.
Add frozen modules to sys.stdlib_module_names. For example, add
"_frozen_importlib" and "_frozen_importlib_external" names.
Add "list_frozen" command to Programs/_testembed.
Added an invalidate_caches() method to the zipimport.zipimporter class based on the implementation of importlib.FileFinder.invalidate_caches(). This was done by adding a get_files() method and an _archive_mtime attribute to zipimport.zipimporter to check for updates or cache invalidation whenever the cache of files and toc entry information in the zipimporter is accessed.
This approach ensures the code matches the interpreter version.
Previously, PYTHON_FOR_REGEN was used to generate the code, which might
be wrong. The marshal format for code objects has changed with
bpo-42246, commit 877df851. Update the code and the expected code sizes
in ctypes test_frozentable.
This is friendlier to other in-process code that an extension module or
embedding use could pull in such as CGo where tiny stacks are the norm
and sigaltstack() has been used to provide for signal handlers.
Without this, signals received by a process using tiny stacks may lead
to stack overflow crashes.
* Unify behavior in ResourceReaderDefaultsTests and align with the behavior found in importlib_resources.
* Equip NamespaceLoader with a NamespaceReader.
* Apply changes from importlib_resources 5.0.4
* No longer save/restore the current exception. It is no longer used
with an exception raised.
* No longer clear the current exception on error: it's now up to the
caller.
The types.FunctionType constructor now inherits the current builtins
if the globals dictionary has no "__builtins__" key, rather than
using {"None": None} as builtins: same behavior as eval() and exec()
functions.
Defining a function with "def function(...): ..." in Python is not
affected, globals cannot be overriden with this syntax: it also
inherits the current builtins.
PyFrame_New(), PyEval_EvalCode(), PyEval_EvalCodeEx(),
PyFunction_New() and PyFunction_NewWithQualName() now inherits the
current builtins namespace if the globals dictionary has no
"__builtins__" key.
* Add _PyEval_GetBuiltins() function.
* _PyEval_BuiltinsFromGlobals() now uses _PyEval_GetBuiltins() if
builtins cannot be found in globals.
* Add tstate parameter to _PyEval_BuiltinsFromGlobals().
Include/{odictobject.h,parser_interface.h,picklebufobject.h,pydebug.h,pyfpe.h}
into Include/cpython/.
Parser: peg_api: include Python.h instead of parser_interface.h.
Pass the current interpreter (interp) rather than the current Python
thread state (tstate) to internal functions which only use the
interpreter.
Modified functions:
* _PyXXX_Fini() and _PyXXX_ClearFreeList() functions
* _PyEval_SignalAsyncExc(), make_pending_calls()
* _PySys_GetObject(), sys_set_object(), sys_set_object_id(), sys_set_object_str()
* should_audit(), set_flags_from_config(), make_flags()
* _PyAtExit_Call()
* init_stdio_encoding()
* etc.