Deprecations

Pending Removal in Python 3.13

Modules (see PEP 594):

• aifc

• audioop

• cgi

• cgitb

• chunk

• crypt

• imghdr

• mailcap

• msilib

• nis

• nntplib

• ossaudiodev

• pipes

• sndhdr

• spwd

• sunau

• telnetlib

• uu

• xdrlib

Other modules:

• lib2to3, and the 2to3 program (gh-84540)

APIs:

• configparser.LegacyInterpolation (gh-90765)

• locale.resetlocale() (gh-90817)

• turtle.RawTurtle.settiltangle() (gh-50096)

• unittest.findTestCases() (gh-50096)

• unittest.getTestCaseNames() (gh-50096)

• unittest.makeSuite() (gh-50096)

• unittest.TestProgram.usageExit() (gh-67048)

• webbrowser.MacOSX (gh-86421)

• classmethod descriptor chaining (gh-89519)

• importlib.resources deprecated methods:

  • contents()

  • is_resource()

  • open_binary()

  • open_text()

  • path()

  • read_binary()

  • read_text()

  Use importlib.resources.files() instead. Refer to importlib-resources: Migrating from Legacy (gh-106531)

Pending Removal in Python 3.14

• argparse: The type, choices, and metavar parameters of argparse.BooleanOptionalAction are deprecated and will be removed in 3.14. (Contributed by Nikita Sobolev in gh-92248.)

• ast: The following features have been deprecated in documentation since Python 3.8, now cause a DeprecationWarning to be emitted at runtime when they are accessed or used, and will be removed in Python 3.14:

  • ast.Num

  • ast.Str

  • ast.Bytes

  • ast.NameConstant

  • ast.Ellipsis

  Use ast.Constant instead. (Contributed by Serhiy Storchaka in gh-90953.)

• asyncio:

  • The child watcher classes MultiLoopChildWatcher, FastChildWatcher, AbstractChildWatcher and SafeChildWatcher are deprecated and will be removed in Python 3.14. (Contributed by Kumar Aditya in gh-94597.)

  • asyncio.set_child_watcher(), asyncio.get_child_watcher(), asyncio.AbstractEventLoopPolicy.set_child_watcher() and asyncio.AbstractEventLoopPolicy.get_child_watcher() are deprecated and will be removed in Python 3.14. (Contributed by Kumar Aditya in gh-94597.)

  • The get_event_loop() method of the default event loop policy now emits a DeprecationWarning if there is no current event loop set and it decides to create one. (Contributed by Serhiy Storchaka and Guido van Rossum in gh-100160.)

• collections.abc: Deprecated ByteString. Prefer Sequence or Buffer. For use in typing, prefer a union, like bytes | bytearray, or collections.abc.Buffer. (Contributed by Shantanu Jain in gh-91896.)

• email: Deprecated the isdst parameter in email.utils.localtime(). (Contributed by Alan Williams in gh-72346.)

• importlib: __package__ and __cached__ will cease to be set or taken into consideration by the import system (gh-97879).

• importlib.abc deprecated classes:

  • importlib.abc.ResourceReader

  • importlib.abc.Traversable

  • importlib.abc.TraversableResources

  Use importlib.resources.abc classes instead:

  • importlib.resources.abc.Traversable

  • importlib.resources.abc.TraversableResources

  (Contributed by Jason R. Coombs and Hugo van Kemenade in gh-93963.)

• itertools had undocumented, inefficient, historically buggy, and inconsistent support for copy, deepcopy, and pickle operations. This will be removed in 3.14 for a significant reduction in code volume and maintenance burden. (Contributed by Raymond Hettinger in gh-101588.)

• multiprocessing: The default start method will change to a safer one on Linux, BSDs, and other non-macOS POSIX platforms where 'fork' is currently the default (gh-84559). Adding a runtime warning about this was deemed too disruptive as the majority of code is not expected to care. Use the get_context() or set_start_method() APIs to explicitly specify when your code requires 'fork'. See Contexts and start methods.

• pathlib: is_relative_to() and relative_to(): passing additional arguments is deprecated.

• pkgutil: find_loader() and get_loader() now raise DeprecationWarning; use importlib.util.find_spec() instead. (Contributed by Nikita Sobolev in gh-97850.)

• pty:

  • master_open(): use pty.openpty().

  • slave_open(): use pty.openpty().

• sqlite3:

  • version and version_info.

  • execute() and executemany() if named placeholders are used and parameters is a sequence instead of a dict.

• typing: ByteString, deprecated since Python 3.9, now causes a DeprecationWarning to be emitted when it is used.

• urllib: urllib.parse.Quoter is deprecated: it was not intended to be a public API. (Contributed by Gregory P. Smith in gh-88168.)

Pending Removal in Python 3.15

• http.server.CGIHTTPRequestHandler will be removed along with its related --cgi flag to python -m http.server. It was obsolete and rarely used. No direct replacement exists. Anything is better than CGI to interface a web server with a request handler.

• locale: locale.getdefaultlocale() was deprecated in Python 3.11 and originally planned for removal in Python 3.13 (gh-90817), but removal has been postponed to Python 3.15. Use locale.setlocale(), locale.getencoding() and locale.getlocale() instead. (Contributed by Hugo van Kemenade in gh-111187.)

• pathlib: pathlib.PurePath.is_reserved() is deprecated and scheduled for removal in Python 3.15. From Python 3.13 onwards, use os.path.isreserved to detect reserved paths on Windows.

• platform: java_ver() is deprecated and will be removed in 3.15. It was largely untested, had a confusing API, and was only useful for Jython support. (Contributed by Nikita Sobolev in gh-116349.)

• threading: Passing any arguments to threading.RLock() is now deprecated. C version allows any numbers of args and kwargs, but they are just ignored. Python version does not allow any arguments. All arguments will be removed from threading.RLock() in Python 3.15. (Contributed by Nikita Sobolev in gh-102029.)

• typing.NamedTuple:

  • The undocumented keyword argument syntax for creating NamedTuple classes (NT = NamedTuple("NT", x=int)) is deprecated, and will be disallowed in 3.15. Use the class-based syntax or the functional syntax instead.

• types:

  • types.CodeType: Accessing co_lnotab was deprecated in PEP 626 since 3.10 and was planned to be removed in 3.12, but it only got a proper DeprecationWarning in 3.12. May be removed in 3.15. (Contributed by Nikita Sobolev in gh-101866.)

• typing:

  • When using the functional syntax to create a NamedTuple class, failing to pass a value to the fields parameter (NT = NamedTuple("NT")) is deprecated. Passing None to the fields parameter (NT = NamedTuple("NT", None)) is also deprecated. Both will be disallowed in Python 3.15. To create a NamedTuple class with 0 fields, use class NT(NamedTuple): pass or NT = NamedTuple("NT", []).

• typing.TypedDict: When using the functional syntax to create a TypedDict class, failing to pass a value to the fields parameter (TD = TypedDict("TD")) is deprecated. Passing None to the fields parameter (TD = TypedDict("TD", None)) is also deprecated. Both will be disallowed in Python 3.15. To create a TypedDict class with 0 fields, use class TD(TypedDict): pass or TD = TypedDict("TD", {}).

• wave: Deprecate the getmark(), setmark() and getmarkers() methods of the wave.Wave_read and wave.Wave_write classes. They will be removed in Python 3.15. (Contributed by Victor Stinner in gh-105096.)

Pending Removal in Python 3.16

• The import system:

  • Setting __loader__ on a module while failing to set __spec__.loader is deprecated. In Python 3.16, __loader__ will cease to be set or taken into consideration by the import system or the standard library.

• array: array.array 'u' type (wchar_t): use the 'w' type instead (Py_UCS4).

• builtins: ~bool, bitwise inversion on bool.

• symtable: Deprecate symtable.Class.get_methods() due to the lack of interest. (Contributed by Bénédikt Tran in gh-119698.)

Pending Removal in Future Versions

The following APIs will be removed in the future, although there is currently no date scheduled for their removal.

• argparse: Nesting argument groups and nesting mutually exclusive groups are deprecated.

• array’s 'u' format code (gh-57281)

• builtins:

  • bool(NotImplemented).

  • Generators: throw(type, exc, tb) and athrow(type, exc, tb) signature is deprecated: use throw(exc) and athrow(exc) instead, the single argument signature.

  • Currently Python accepts numeric literals immediately followed by keywords, for example 0in x, 1or x, 0if 1else 2. It allows confusing and ambiguous expressions like [0x1for x in y] (which can be interpreted as [0x1 for x in y] or [0x1f or x in y]). A syntax warning is raised if the numeric literal is immediately followed by one of keywords and, else, for, if, in, is and or. In a future release it will be changed to a syntax error. (gh-87999)

  • Support for __index__() and __int__() method returning non-int type: these methods will be required to return an instance of a strict subclass of int.

  • Support for __float__() method returning a strict subclass of float: these methods will be required to return an instance of float.

  • Support for __complex__() method returning a strict subclass of complex: these methods will be required to return an instance of complex.

  • Delegation of int() to __trunc__() method.

  • Passing a complex number as the real or imag argument in the complex() constructor is now deprecated; it should only be passed as a single positional argument. (Contributed by Serhiy Storchaka in gh-109218.)

• calendar: calendar.January and calendar.February constants are deprecated and replaced by calendar.JANUARY and calendar.FEBRUARY. (Contributed by Prince Roshan in gh-103636.)

• codeobject.co_lnotab: use the codeobject.co_lines() method instead.

• datetime:

  • utcnow(): use datetime.datetime.now(tz=datetime.UTC).

  • utcfromtimestamp(): use datetime.datetime.fromtimestamp(timestamp, tz=datetime.UTC).

• gettext: Plural value must be an integer.

• importlib:

  • load_module() method: use exec_module() instead.

  • cache_from_source() debug_override parameter is deprecated: use the optimization parameter instead.

• importlib.metadata:

  • EntryPoints tuple interface.

  • Implicit None on return values.

• mailbox: Use of StringIO input and text mode is deprecated, use BytesIO and binary mode instead.

• os: Calling os.register_at_fork() in multi-threaded process.

• pydoc.ErrorDuringImport: A tuple value for exc_info parameter is deprecated, use an exception instance.

• re: More strict rules are now applied for numerical group references and group names in regular expressions. Only sequence of ASCII digits is now accepted as a numerical reference. The group name in bytes patterns and replacement strings can now only contain ASCII letters and digits and underscore. (Contributed by Serhiy Storchaka in gh-91760.)

• sre_compile, sre_constants and sre_parse modules.

• shutil: rmtree()’s onerror parameter is deprecated in Python 3.12; use the onexc parameter instead.

• ssl options and protocols:

  • ssl.SSLContext without protocol argument is deprecated.

  • ssl.SSLContext: set_npn_protocols() and selected_npn_protocol() are deprecated: use ALPN instead.

  • ssl.OP_NO_SSL* options

  • ssl.OP_NO_TLS* options

  • ssl.PROTOCOL_SSLv3

  • ssl.PROTOCOL_TLS

  • ssl.PROTOCOL_TLSv1

  • ssl.PROTOCOL_TLSv1_1

  • ssl.PROTOCOL_TLSv1_2

  • ssl.TLSVersion.SSLv3

  • ssl.TLSVersion.TLSv1

  • ssl.TLSVersion.TLSv1_1

• sysconfig.is_python_build() check_home parameter is deprecated and ignored.

• threading methods:

  • threading.Condition.notifyAll(): use notify_all().

  • threading.Event.isSet(): use is_set().

  • threading.Thread.isDaemon(), threading.Thread.setDaemon(): use threading.Thread.daemon attribute.

  • threading.Thread.getName(), threading.Thread.setName(): use threading.Thread.name attribute.

  • threading.currentThread(): use threading.current_thread().

  • threading.activeCount(): use threading.active_count().

• typing.Text (gh-92332).

• unittest.IsolatedAsyncioTestCase: it is deprecated to return a value that is not None from a test case.

• urllib.parse deprecated functions: urlparse() instead

  • splitattr()

  • splithost()

  • splitnport()

  • splitpasswd()

  • splitport()

  • splitquery()

  • splittag()

  • splittype()

  • splituser()

  • splitvalue()

  • to_bytes()

• urllib.request: URLopener and FancyURLopener style of invoking requests is deprecated. Use newer urlopen() functions and methods.

• wsgiref: SimpleHandler.stdout.write() should not do partial writes.

• xml.etree.ElementTree: Testing the truth value of an Element is deprecated. In a future release it will always return True. Prefer explicit len(elem) or elem is not None tests instead.

• zipimport.zipimporter.load_module() is deprecated: use exec_module() instead.

C API Deprecations

Pending Removal in Python 3.14

• The ma_version_tag field in PyDictObject for extension modules (PEP 699; gh-101193).

• Creating immutable types with mutable bases (gh-95388).

• Functions to configure Python’s initialization, deprecated in Python 3.11:

  • PySys_SetArgvEx(): Set PyConfig.argv instead.

  • PySys_SetArgv(): Set PyConfig.argv instead.

  • Py_SetProgramName(): Set PyConfig.program_name instead.

  • Py_SetPythonHome(): Set PyConfig.home instead.

  The Py_InitializeFromConfig() API should be used with PyConfig instead.

• Global configuration variables:

  • Py_DebugFlag: Use PyConfig.parser_debug instead.

  • Py_VerboseFlag: Use PyConfig.verbose instead.

  • Py_QuietFlag: Use PyConfig.quiet instead.

  • Py_InteractiveFlag: Use PyConfig.interactive instead.

  • Py_InspectFlag: Use PyConfig.inspect instead.

  • Py_OptimizeFlag: Use PyConfig.optimization_level instead.

  • Py_NoSiteFlag: Use PyConfig.site_import instead.

  • Py_BytesWarningFlag: Use PyConfig.bytes_warning instead.

  • Py_FrozenFlag: Use PyConfig.pathconfig_warnings instead.

  • Py_IgnoreEnvironmentFlag: Use PyConfig.use_environment instead.

  • Py_DontWriteBytecodeFlag: Use PyConfig.write_bytecode instead.

  • Py_NoUserSiteDirectory: Use PyConfig.user_site_directory instead.

  • Py_UnbufferedStdioFlag: Use PyConfig.buffered_stdio instead.

  • Py_HashRandomizationFlag: Use PyConfig.use_hash_seed and PyConfig.hash_seed instead.

  • Py_IsolatedFlag: Use PyConfig.isolated instead.

  • Py_LegacyWindowsFSEncodingFlag: Use PyPreConfig.legacy_windows_fs_encoding instead.

  • Py_LegacyWindowsStdioFlag: Use PyConfig.legacy_windows_stdio instead.

  • Py_FileSystemDefaultEncoding: Use PyConfig.filesystem_encoding instead.

  • Py_HasFileSystemDefaultEncoding: Use PyConfig.filesystem_encoding instead.

  • Py_FileSystemDefaultEncodeErrors: Use PyConfig.filesystem_errors instead.

  • Py_UTF8Mode: Use PyPreConfig.utf8_mode instead. (see Py_PreInitialize())

  The Py_InitializeFromConfig() API should be used with PyConfig instead.

Pending Removal in Python 3.15

• The bundled copy of libmpdecimal.

• The PyImport_ImportModuleNoBlock(): Use PyImport_ImportModule() instead.

• PyWeakref_GetObject() and PyWeakref_GET_OBJECT(): Use PyWeakref_GetRef() instead.

• Py_UNICODE type and the Py_UNICODE_WIDE macro: Use wchar_t instead.

• Python initialization functions:

  • PySys_ResetWarnOptions(): Clear sys.warnoptions and warnings.filters instead.

  • Py_GetExecPrefix(): Get sys.exec_prefix instead.

  • Py_GetPath(): Get sys.path instead.

  • Py_GetPrefix(): Get sys.prefix instead.

  • Py_GetProgramFullPath(): Get sys.executable instead.

  • Py_GetProgramName(): Get sys.executable instead.

  • Py_GetPythonHome(): Get PyConfig.home or the PYTHONHOME environment variable instead.

Pending Removal in Future Versions

The following APIs are deprecated and will be removed, although there is currently no date scheduled for their removal.

• Py_TPFLAGS_HAVE_FINALIZE: Unneeded since Python 3.8.

• PyErr_Fetch(): Use PyErr_GetRaisedException() instead.

• PyErr_NormalizeException(): Use PyErr_GetRaisedException() instead.

• PyErr_Restore(): Use PyErr_SetRaisedException() instead.

• PyModule_GetFilename(): Use PyModule_GetFilenameObject() instead.

• PyOS_AfterFork(): Use PyOS_AfterFork_Child() instead.

• PySlice_GetIndicesEx(): Use PySlice_Unpack() and PySlice_AdjustIndices() instead.

• PyUnicode_AsDecodedObject(): Use PyCodec_Decode() instead.

• PyUnicode_AsDecodedUnicode(): Use PyCodec_Decode() instead.

• PyUnicode_AsEncodedObject(): Use PyCodec_Encode() instead.

• PyUnicode_AsEncodedUnicode(): Use PyCodec_Encode() instead.

• PyUnicode_READY(): Unneeded since Python 3.12

• PyErr_Display(): Use PyErr_DisplayException() instead.

• _PyErr_ChainExceptions(): Use _PyErr_ChainExceptions1() instead.

• PyBytesObject.ob_shash member: call PyObject_Hash() instead.

• PyDictObject.ma_version_tag member.

• Thread Local Storage (TLS) API:

  • PyThread_create_key(): Use PyThread_tss_alloc() instead.

  • PyThread_delete_key(): Use PyThread_tss_free() instead.

  • PyThread_set_key_value(): Use PyThread_tss_set() instead.

  • PyThread_get_key_value(): Use PyThread_tss_get() instead.

  • PyThread_delete_key_value(): Use PyThread_tss_delete() instead.

  • PyThread_ReInitTLS(): Unneeded since Python 3.7.