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 コンテキストと開始方式.

* "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.
