Deprecations

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. 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.

  • 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

• 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.)

• shutil: Deprecate shutil.ExecError, which hasn’t been raised by any shutil function since Python 3.4. It’s now an alias for RuntimeError.

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.

• logging: the warn() method has been deprecated since Python 3.3, use warning() instead.

• 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 3.15

• The bundled copy of libmpdecimal.

• PyImport_ImportModuleNoBlock(): use PyImport_ImportModule() instead.

• PyWeakref_GET_OBJECT(): use PyWeakref_GetRef() instead.

• PyWeakref_GetObject(): use PyWeakref_GetRef() instead.

• Py_UNICODE_WIDE type: use wchar_t instead.

• Py_UNICODE type: 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.