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
This test checks result code of the connection directly, so it never raises an exception that can be suppressed by `support.transient_internet`. Directly support skipping the test in case of unreachable network.
It doesn't actually affect whether match_hostname() is called (it
never is in this context any longer), but whether hostname
verification occurs in the first place.
This reverts commit 32f2eda859.
It can be re-applied if the subinterpreter PEP is approved.
Otherwise, the commit degraded performance with no offsetting
benefit.
pprint() gains a new boolean underscore_numbers kwarg to emit
integers with thousands separated by an underscore character
for improved readability (for example 1_000_000 instead of 1000000).
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.
Reduce the number of modules imported by "python3 -m module".
The runpy module no longer imports at startup (in the module body),
but only in functions using it: _get_code_from_file() and run_path().
RegressionTestResult.USE_XML must now be set to True to get the JUnit
XML output.
Reduce the number of imports when --junit-xml=FILE option is not
used: 153 => 144 (-9).
Move clear_caches() from libregrtest.refleak to libregrtest.utils to
avoid importing libregrtest.refleak when it's not needed.
clear_caches() now only calls re.purge() if 're' is in sys.modules.
Reduce the number of modules imported by libregrtest.
saved_test_environment no longer imports modules at startup, but try
to get them from sys.modules. If an module is missing, skip the test.
It also sets directly support.environment_altered.
runtest() now now two saved_test_environment instances: one before
importing the test module, one after importing it.
Remove imports from test.libregrtest.save_env:
* asyncio
* logging
* multiprocessing
* shutil
* sysconfig
* urllib.request
* warnings
When a test method imports a module (ex: warnings) and the test
has a side effect (ex: add a warnings filter), the side effect is not
detected, because the module was not imported when Python
enters the saved_test_environment context manager.
