Deprecations¶
Pending Removal in Python 3.14¶
The import system:
Setting
__loader__
on a module while failing to set__spec__.loader
is deprecated. In Python 3.14,__loader__
will cease to be set or taken into consideration by the import system or the standard library.
argparse
: The type, choices, and metavar parameters ofargparse.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 aDeprecationWarning
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.)-
The child watcher classes
MultiLoopChildWatcher
,FastChildWatcher
,AbstractChildWatcher
andSafeChildWatcher
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()
andasyncio.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 aDeprecationWarning
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
: DeprecatedByteString
. PreferSequence
orBuffer
. For use in typing, prefer a union, likebytes | bytearray
, orcollections.abc.Buffer
. (Contributed by Shantanu Jain in gh-91896.)email
: Deprecated the isdst parameter inemail.utils.localtime()
. (Contributed by Alan Williams in gh-72346.)importlib.abc
deprecated classes:importlib.abc.ResourceReader
importlib.abc.Traversable
importlib.abc.TraversableResources
Use
importlib.resources.abc
classes instead:(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 theget_context()
orset_start_method()
APIs to explicitly specify when your code requires'fork'
. See Contexts and start methods.pathlib
:is_relative_to()
andrelative_to()
: passing additional arguments is deprecated.pkgutil
:find_loader()
andget_loader()
now raiseDeprecationWarning
; useimportlib.util.find_spec()
instead. (Contributed by Nikita Sobolev in gh-97850.)pty
:master_open()
: usepty.openpty()
.slave_open()
: usepty.openpty()
.
-
version
andversion_info
.execute()
andexecutemany()
if named placeholders are used and parameters is a sequence instead of adict
.
typing
:ByteString
, deprecated since Python 3.9, now causes aDeprecationWarning
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¶
The import system:
Setting
__cached__
on a module while failing to set__spec__.cached
is deprecated. In Python 3.15,__cached__
will cease to be set or take into consideration by the import system or standard library. (gh-97879)Setting
__package__
on a module while failing to set__spec__.parent
is deprecated. In Python 3.15,__package__
will cease to be set or take into consideration by the import system or standard library. (gh-97879)
-
The undocumented
ctypes.SetPointerType()
function has been deprecated since Python 3.13.
-
The obsolete and rarely used
CGIHTTPRequestHandler
has been deprecated since Python 3.13. No direct replacement exists. Anything is better than CGI to interface a web server with a request handler.The
--cgi
flag to the python -m http.server command-line interface has been deprecated since Python 3.13.
-
The
getdefaultlocale()
function has been deprecated since Python 3.11. Its removal was originally planned for Python 3.13 (gh-90817), but has been postponed to Python 3.15. Usegetlocale()
,setlocale()
, andgetencoding()
instead. (Contributed by Hugo van Kemenade in gh-111187.)
-
PurePath.is_reserved()
has been deprecated since Python 3.13. Useos.path.isreserved()
to detect reserved paths on Windows.
-
java_ver()
has been deprecated since Python 3.13. This function is only useful for Jython support, has a confusing API, and is largely untested.
-
RLock()
will take no arguments in Python 3.15. Passing any arguments has been deprecated since Python 3.14, as the Python version does not permit any arguments, but the C version allows any number of positional or keyword arguments, ignoring every argument.
-
types.CodeType
: Accessingco_lnotab
was deprecated in PEP 626 since 3.10 and was planned to be removed in 3.12, but it only got a properDeprecationWarning
in 3.12. May be removed in 3.15. (Contributed by Nikita Sobolev in gh-101866.)
-
The undocumented keyword argument syntax for creating
NamedTuple
classes (e.g.Point = NamedTuple("Point", x=int, y=int)
) has been deprecated since Python 3.13. Use the class-based syntax or the functional syntax instead.The
typing.no_type_check_decorator()
decorator function has been deprecated since Python 3.13. After eight years in thetyping
module, it has yet to be supported by any major type checker.
wave
:The
getmark()
,setmark()
, andgetmarkers()
methods of theWave_read
andWave_write
classes have been deprecated since Python 3.13.
Pending Removal in Python 3.16¶
-
Bitwise inversion on boolean types,
~True
or~False
has been deprecated since Python 3.12, as it produces surprising and unintuitive results (-2
and-1
). Usenot x
instead for the logical negation of a Boolean. In the rare case that you need the bitwise inversion of the underlying integer, convert toint
explicitly (~int(x)
).
-
The
'u'
format code (wchar_t
) has been deprecated in documentation since Python 3.3 and at runtime since Python 3.13. Use the'w'
format code (Py_UCS4
) for Unicode characters instead.
-
The
ExecError
exception has been deprecated since Python 3.14. It has not been used by any function inshutil
since Python 3.4, and is now an alias ofRuntimeError
.
-
The
Class.get_methods
method has been deprecated since Python 3.14.
sys
:The
_enablelegacywindowsfsencoding()
function has been deprecated since Python 3.13. Use thePYTHONLEGACYWINDOWSFSENCODING
environment variable instead.
-
The undocumented and unused
TarFile.tarfile
attribute has been deprecated since Python 3.13.
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.-
bool(NotImplemented)
.Generators:
throw(type, exc, tb)
andathrow(type, exc, tb)
signature is deprecated: usethrow(exc)
andathrow(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 keywordsand
,else
,for
,if
,in
,is
andor
. 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 ofint
.Support for
__float__()
method returning a strict subclass offloat
: these methods will be required to return an instance offloat
.Support for
__complex__()
method returning a strict subclass ofcomplex
: these methods will be required to return an instance ofcomplex
.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
andcalendar.February
constants are deprecated and replaced bycalendar.JANUARY
andcalendar.FEBRUARY
. (Contributed by Prince Roshan in gh-103636.)codeobject.co_lnotab
: use thecodeobject.co_lines()
method instead.-
utcnow()
: usedatetime.datetime.now(tz=datetime.UTC)
.utcfromtimestamp()
: usedatetime.datetime.fromtimestamp(timestamp, tz=datetime.UTC)
.
gettext
: Plural value must be an integer.-
load_module()
method: useexec_module()
instead.cache_from_source()
debug_override parameter is deprecated: use the optimization parameter instead.
-
EntryPoints
tuple interface.Implicit
None
on return values.
logging
: thewarn()
method has been deprecated since Python 3.3, usewarning()
instead.mailbox
: Use of StringIO input and text mode is deprecated, use BytesIO and binary mode instead.os
: Callingos.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
andsre_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()
andselected_npn_protocol()
are deprecated: use ALPN instead.ssl.OP_NO_SSL*
optionsssl.OP_NO_TLS*
optionsssl.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()
: usenotify_all()
.threading.Event.isSet()
: useis_set()
.threading.Thread.isDaemon()
,threading.Thread.setDaemon()
: usethreading.Thread.daemon
attribute.threading.Thread.getName()
,threading.Thread.setName()
: usethreading.Thread.name
attribute.threading.currentThread()
: usethreading.current_thread()
.threading.activeCount()
: usethreading.active_count()
.
unittest.IsolatedAsyncioTestCase
: it is deprecated to return a value that is notNone
from a test case.urllib.parse
deprecated functions:urlparse()
insteadsplitattr()
splithost()
splitnport()
splitpasswd()
splitport()
splitquery()
splittag()
splittype()
splituser()
splitvalue()
to_bytes()
urllib.request
:URLopener
andFancyURLopener
style of invoking requests is deprecated. Use newerurlopen()
functions and methods.wsgiref
:SimpleHandler.stdout.write()
should not do partial writes.xml.etree.ElementTree
: Testing the truth value of anElement
is deprecated. In a future release it will always returnTrue
. Prefer explicitlen(elem)
orelem is not None
tests instead.zipimport.zipimporter.load_module()
is deprecated: useexec_module()
instead.
C API Deprecations¶
Pending Removal in Python 3.14¶
The
ma_version_tag
field inPyDictObject
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()
: SetPyConfig.argv
instead.PySys_SetArgv()
: SetPyConfig.argv
instead.Py_SetProgramName()
: SetPyConfig.program_name
instead.Py_SetPythonHome()
: SetPyConfig.home
instead.
The
Py_InitializeFromConfig()
API should be used withPyConfig
instead.Global configuration variables:
Py_DebugFlag
: UsePyConfig.parser_debug
instead.Py_VerboseFlag
: UsePyConfig.verbose
instead.Py_QuietFlag
: UsePyConfig.quiet
instead.Py_InteractiveFlag
: UsePyConfig.interactive
instead.Py_InspectFlag
: UsePyConfig.inspect
instead.Py_OptimizeFlag
: UsePyConfig.optimization_level
instead.Py_NoSiteFlag
: UsePyConfig.site_import
instead.Py_BytesWarningFlag
: UsePyConfig.bytes_warning
instead.Py_FrozenFlag
: UsePyConfig.pathconfig_warnings
instead.Py_IgnoreEnvironmentFlag
: UsePyConfig.use_environment
instead.Py_DontWriteBytecodeFlag
: UsePyConfig.write_bytecode
instead.Py_NoUserSiteDirectory
: UsePyConfig.user_site_directory
instead.Py_UnbufferedStdioFlag
: UsePyConfig.buffered_stdio
instead.Py_HashRandomizationFlag
: UsePyConfig.use_hash_seed
andPyConfig.hash_seed
instead.Py_IsolatedFlag
: UsePyConfig.isolated
instead.Py_LegacyWindowsFSEncodingFlag
: UsePyPreConfig.legacy_windows_fs_encoding
instead.Py_LegacyWindowsStdioFlag
: UsePyConfig.legacy_windows_stdio
instead.Py_FileSystemDefaultEncoding
: UsePyConfig.filesystem_encoding
instead.Py_HasFileSystemDefaultEncoding
: UsePyConfig.filesystem_encoding
instead.Py_FileSystemDefaultEncodeErrors
: UsePyConfig.filesystem_errors
instead.Py_UTF8Mode
: UsePyPreConfig.utf8_mode
instead. (seePy_PreInitialize()
)
The
Py_InitializeFromConfig()
API should be used withPyConfig
instead.
Pending Removal in Python 3.15¶
The bundled copy of
libmpdecimal
.The
PyImport_ImportModuleNoBlock()
: UsePyImport_ImportModule()
instead.PyWeakref_GetObject()
andPyWeakref_GET_OBJECT()
: UsePyWeakref_GetRef()
instead.Py_UNICODE
type and thePy_UNICODE_WIDE
macro: Usewchar_t
instead.Python initialization functions:
PySys_ResetWarnOptions()
: Clearsys.warnoptions
andwarnings.filters
instead.Py_GetExecPrefix()
: Getsys.base_exec_prefix
andsys.exec_prefix
instead.Py_GetPath()
: Getsys.path
instead.Py_GetPrefix()
: Getsys.base_prefix
andsys.prefix
instead.Py_GetProgramFullPath()
: Getsys.executable
instead.Py_GetProgramName()
: Getsys.executable
instead.Py_GetPythonHome()
: GetPyConfig.home
or thePYTHONHOME
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()
: UsePyErr_GetRaisedException()
instead.PyErr_NormalizeException()
: UsePyErr_GetRaisedException()
instead.PyErr_Restore()
: UsePyErr_SetRaisedException()
instead.PyModule_GetFilename()
: UsePyModule_GetFilenameObject()
instead.PyOS_AfterFork()
: UsePyOS_AfterFork_Child()
instead.PySlice_GetIndicesEx()
: UsePySlice_Unpack()
andPySlice_AdjustIndices()
instead.PyUnicode_AsDecodedObject()
: UsePyCodec_Decode()
instead.PyUnicode_AsDecodedUnicode()
: UsePyCodec_Decode()
instead.PyUnicode_AsEncodedObject()
: UsePyCodec_Encode()
instead.PyUnicode_AsEncodedUnicode()
: UsePyCodec_Encode()
instead.PyUnicode_READY()
: Unneeded since Python 3.12PyErr_Display()
: UsePyErr_DisplayException()
instead._PyErr_ChainExceptions()
: Use_PyErr_ChainExceptions1()
instead.PyBytesObject.ob_shash
member: callPyObject_Hash()
instead.PyDictObject.ma_version_tag
member.Thread Local Storage (TLS) API:
PyThread_create_key()
: UsePyThread_tss_alloc()
instead.PyThread_delete_key()
: UsePyThread_tss_free()
instead.PyThread_set_key_value()
: UsePyThread_tss_set()
instead.PyThread_get_key_value()
: UsePyThread_tss_get()
instead.PyThread_delete_key_value()
: UsePyThread_tss_delete()
instead.PyThread_ReInitTLS()
: Unneeded since Python 3.7.