read from a Python bytecode file or obtained from the built-in function
:func:`compile`, load the module. Return a new reference to the module object,
or ``NULL`` with an exception set if an error occurred. *name*
- is removed from :attr:`sys.modules` in error cases, even if *name* was already
- in :attr:`sys.modules` on entry to :c:func:`PyImport_ExecCodeModule`. Leaving
- incompletely initialized modules in :attr:`sys.modules` is dangerous, as imports of
+ is removed from :data:`sys.modules` in error cases, even if *name* was already
+ in :data:`sys.modules` on entry to :c:func:`PyImport_ExecCodeModule`. Leaving
+ incompletely initialized modules in :data:`sys.modules` is dangerous, as imports of
such modules have no way to know that the module object is an unknown (and
probably damaged with respect to the module author's intents) state.
running top-level code meant for script use which is put in the
``if __name__ == "__main__"`` block of the ``start`` module. Why does this work?
-Python inserts an empty ``__main__`` module in :attr:`sys.modules` at
+Python inserts an empty ``__main__`` module in :data:`sys.modules` at
interpreter startup, and populates it by running top-level code. In our example
this is the ``start`` module which runs line by line and imports ``namely``.
In turn, ``namely`` imports ``__main__`` (which is really ``start``). That's an
import cycle! Fortunately, since the partially populated ``__main__``
-module is present in :attr:`sys.modules`, Python passes that to ``namely``.
+module is present in :data:`sys.modules`, Python passes that to ``namely``.
See :ref:`Special considerations for __main__ <import-dunder-main>` in the
import system's reference for details on how this works.
The *limit* argument sets the buffer limit for :class:`StreamReader`
wrappers for :attr:`Process.stdout` and :attr:`Process.stderr`
- (if :attr:`subprocess.PIPE` is passed to *stdout* and *stderr* arguments).
+ (if :const:`subprocess.PIPE` is passed to *stdout* and *stderr* arguments).
Return a :class:`~asyncio.subprocess.Process` instance.
The *limit* argument sets the buffer limit for :class:`StreamReader`
wrappers for :attr:`Process.stdout` and :attr:`Process.stderr`
- (if :attr:`subprocess.PIPE` is passed to *stdout* and *stderr* arguments).
+ (if :const:`subprocess.PIPE` is passed to *stdout* and *stderr* arguments).
Return a :class:`~asyncio.subprocess.Process` instance.
:func:`compile` function, because the Python interpreter itself already
provides the option: :program:`python -O -m compileall`.
-Similarly, the :func:`compile` function respects the :attr:`sys.pycache_prefix`
+Similarly, the :func:`compile` function respects the :data:`sys.pycache_prefix`
setting. The generated bytecode cache will only be useful if :func:`compile` is
-run with the same :attr:`sys.pycache_prefix` (if any) that will be used at
+run with the same :data:`sys.pycache_prefix` (if any) that will be used at
runtime.
Public functions
ignored for empty strings.
* The :class:`io.IOBase` destructor logs ``close()`` exceptions.
-* Set the :attr:`~sys.flags.dev_mode` attribute of :attr:`sys.flags` to
+* Set the :attr:`~sys.flags.dev_mode` attribute of :data:`sys.flags` to
``True``.
The Python Development Mode does not enable the :mod:`tracemalloc` module by
Construct a new directory comparison object, to compare the directories *a*
and *b*. *ignore* is a list of names to ignore, and defaults to
- :attr:`filecmp.DEFAULT_IGNORES`. *hide* is a list of names to hide, and
+ :const:`filecmp.DEFAULT_IGNORES`. *hide* is a list of names to hide, and
defaults to ``[os.curdir, os.pardir]``.
The :class:`dircmp` class compares files by doing *shallow* comparisons
.. attribute:: FTP_TLS.ssl_version
- The SSL version to use (defaults to :attr:`ssl.PROTOCOL_SSLv23`).
+ The SSL version to use (defaults to :data:`ssl.PROTOCOL_SSLv23`).
.. method:: FTP_TLS.auth()
* Binary files are buffered in fixed-size chunks; the size of the buffer is
chosen using a heuristic trying to determine the underlying device's "block
- size" and falling back on :attr:`io.DEFAULT_BUFFER_SIZE`. On many systems,
+ size" and falling back on :const:`io.DEFAULT_BUFFER_SIZE`. On many systems,
the buffer will typically be 4096 or 8192 bytes long.
* "Interactive" text files (files for which :meth:`~io.IOBase.isatty`
.. versionchanged:: 3.4
Following :pep:`442`, objects with a :meth:`__del__` method don't end
- up in :attr:`gc.garbage` anymore.
+ up in :data:`gc.garbage` anymore.
.. data:: callbacks
.. cmdoption:: file
- If *file* is not specified, read from :attr:`sys.stdin`.
+ If *file* is not specified, read from :data:`sys.stdin`.
.. cmdoption:: --fast
suitable for reading (same as :attr:`pathlib.Path.open`).
When opening as text, accepts encoding parameters such as those
- accepted by :attr:`io.TextIOWrapper`.
+ accepted by :class:`io.TextIOWrapper`.
.. method:: read_bytes()
The list of locations where the package's submodules will be found.
Most of the time this is a single directory.
The import system passes this attribute to ``__import__()`` and to finders
- in the same way as :attr:`sys.path` but just for the package.
+ in the same way as :data:`sys.path` but just for the package.
It is not set on non-package modules so it can be used
as an indicator that the module is a package.
automatically.
When writing to the path fails because the path is read-only
- (:attr:`errno.EACCES`/:exc:`PermissionError`), do not propagate the
+ (:const:`errno.EACCES`/:exc:`PermissionError`), do not propagate the
exception.
.. versionchanged:: 3.4
.. classmethod:: path_hook(*loader_details)
- A class method which returns a closure for use on :attr:`sys.path_hooks`.
+ A class method which returns a closure for use on :data:`sys.path_hooks`.
An instance of :class:`FileFinder` is returned by the closure using the
path argument given to the closure directly and *loader_details*
indirectly.
.. function:: find_spec(name, package=None)
Find the :term:`spec <module spec>` for a module, optionally relative to
- the specified **package** name. If the module is in :attr:`sys.modules`,
+ the specified **package** name. If the module is in :data:`sys.modules`,
then ``sys.modules[name].__spec__`` is returned (unless the spec would be
``None`` or is not set, in which case :exc:`ValueError` is raised).
- Otherwise a search using :attr:`sys.meta_path` is done. ``None`` is
+ Otherwise a search using :data:`sys.meta_path` is done. ``None`` is
returned if no spec is found.
If **name** is for a submodule (contains a dot), the parent module is
:meth:`~importlib.abc.Loader.create_module` method must return ``None`` or a
type for which its ``__class__`` attribute can be mutated along with not
using :term:`slots <__slots__>`. Finally, modules which substitute the object
- placed into :attr:`sys.modules` will not work as there is no way to properly
+ placed into :data:`sys.modules` will not work as there is no way to properly
replace the module references throughout the interpreter safely;
:exc:`ValueError` is raised if such a substitution is detected.
:term:`importer`. This means managing both the :term:`finder` and :term:`loader`
side of things. For finders there are two flavours to choose from depending on
your needs: a :term:`meta path finder` or a :term:`path entry finder`. The
-former is what you would put on :attr:`sys.meta_path` while the latter is what
-you create using a :term:`path entry hook` on :attr:`sys.path_hooks` which works
-with :attr:`sys.path` entries to potentially create a finder. This example will
+former is what you would put on :data:`sys.meta_path` while the latter is what
+you create using a :term:`path entry hook` on :data:`sys.path_hooks` which works
+with :data:`sys.path` entries to potentially create a finder. This example will
show you how to register your own importers so that import will use them (for
creating an importer for yourself, read the documentation for the appropriate
classes defined within this package)::
and pretty-print JSON objects.
If the optional ``infile`` and ``outfile`` arguments are not
-specified, :attr:`sys.stdin` and :attr:`sys.stdout` will be used respectively:
+specified, :data:`sys.stdin` and :data:`sys.stdout` will be used respectively:
.. code-block:: shell-session
}
]
- If *infile* is not specified, read from :attr:`sys.stdin`.
+ If *infile* is not specified, read from :data:`sys.stdin`.
.. cmdoption:: outfile
Write the output of the *infile* to the given *outfile*. Otherwise, write it
- to :attr:`sys.stdout`.
+ to :data:`sys.stdout`.
.. cmdoption:: --sort-keys
occur (e.g. because a bounded queue has filled up), the
:meth:`~logging.Handler.handleError` method is called to handle the
error. This can result in the record silently being dropped (if
- :attr:`logging.raiseExceptions` is ``False``) or a message printed to
- ``sys.stderr`` (if :attr:`logging.raiseExceptions` is ``True``).
+ :data:`logging.raiseExceptions` is ``False``) or a message printed to
+ ``sys.stderr`` (if :data:`logging.raiseExceptions` is ``True``).
.. method:: prepare(record)
*start*. On Windows, :exc:`ValueError` is raised when *path* and *start*
are on different drives.
- *start* defaults to :attr:`os.curdir`.
+ *start* defaults to :data:`os.curdir`.
.. availability:: Unix, Windows.
``'java'``.
.. seealso::
- :attr:`sys.platform` has a finer granularity. :func:`os.uname` gives
+ :data:`sys.platform` has a finer granularity. :func:`os.uname` gives
system-dependent version information.
The :mod:`platform` module provides detailed checks for the
universal files containing multiple architectures.
To get at the "64-bitness" of the current interpreter, it is more
- reliable to query the :attr:`sys.maxsize` attribute::
+ reliable to query the :data:`sys.maxsize` attribute::
is_64bits = sys.maxsize > 2**32
determining if the file exists and executable.
When no *path* is specified, the results of :func:`os.environ` are used,
- returning either the "PATH" value or a fallback of :attr:`os.defpath`.
+ returning either the "PATH" value or a fallback of :data:`os.defpath`.
On Windows, the current directory is always prepended to the *path* whether
or not you use the default or provide your own, which is the behavior the
a getter and setter for the interpreter-wide limit. Subinterpreters have
their own limit.
-Information about the default and minimum can be found in :attr:`sys.int_info`:
+Information about the default and minimum can be found in :data:`sys.int_info`:
* :data:`sys.int_info.default_max_str_digits <sys.int_info>` is the compiled-in
default limit.
If you ever encounter a presumed highly unusual situation where you need to
prevent ``vfork()`` from being used by Python, you can set the
-:attr:`subprocess._USE_VFORK` attribute to a false value.
+:const:`subprocess._USE_VFORK` attribute to a false value.
::
Setting this has no impact on use of ``posix_spawn()`` which could use
``vfork()`` internally within its libc implementation. There is a similar
-:attr:`subprocess._USE_POSIX_SPAWN` attribute if you need to prevent use of
+:const:`subprocess._USE_POSIX_SPAWN` attribute if you need to prevent use of
that.
::
Python interpreter. (This information is not available in any other way ---
``modules.keys()`` only lists the imported modules.)
- See also the :attr:`sys.stdlib_module_names` list.
+ See also the :data:`sys.stdlib_module_names` list.
.. function:: call_tracing(func, args)
================ ===========================
.. versionchanged:: 3.3
- On Linux, :attr:`sys.platform` doesn't contain the major version anymore.
+ On Linux, :data:`sys.platform` doesn't contain the major version anymore.
It is always ``'linux'``, instead of ``'linux2'`` or ``'linux3'``. Since
older Python versions include the version number, it is recommended to
always use the ``startswith`` idiom presented above.
.. versionchanged:: 3.8
- On AIX, :attr:`sys.platform` doesn't contain the major version anymore.
+ On AIX, :data:`sys.platform` doesn't contain the major version anymore.
It is always ``'aix'``, instead of ``'aix5'`` or ``'aix7'``. Since
older Python versions include the version number, it is recommended to
always use the ``startswith`` idiom presented above.
.. seealso::
- :attr:`os.name` has a coarser granularity. :func:`os.uname` gives
+ :data:`os.name` has a coarser granularity. :func:`os.uname` gives
system-dependent version information.
The :mod:`platform` module provides detailed checks for the
``email.mime`` sub-package and the ``email.message`` sub-module are not
listed.
- See also the :attr:`sys.builtin_module_names` list.
+ See also the :data:`sys.builtin_module_names` list.
.. versionadded:: 3.10
Implements the ``'tar'`` filter.
- - Strip leading slashes (``/`` and :attr:`os.sep`) from filenames.
+ - Strip leading slashes (``/`` and :data:`os.sep`) from filenames.
- :ref:`Refuse <tarfile-extraction-refuse>` to extract files with absolute
paths (in case the name is absolute
even after stripping slashes, e.g. ``C:/foo`` on Windows).
path (after following symlinks) would end up outside the destination.
This raises :class:`~tarfile.OutsideDestinationError`.
- Clear high mode bits (setuid, setgid, sticky) and group/other write bits
- (:attr:`~stat.S_IWGRP`|:attr:`~stat.S_IWOTH`).
+ (:const:`~stat.S_IWGRP`|:const:`~stat.S_IWOTH`).
Return the modified ``TarInfo`` member.
- For regular files, including hard links:
- Set the owner read and write permissions
- (:attr:`~stat.S_IRUSR`|:attr:`~stat.S_IWUSR`).
+ (:const:`~stat.S_IRUSR`|:const:`~stat.S_IWUSR`).
- Remove the group & other executable permission
- (:attr:`~stat.S_IXGRP`|:attr:`~stat.S_IXOTH`)
- if the owner doesn’t have it (:attr:`~stat.S_IXUSR`).
+ (:const:`~stat.S_IXGRP`|:const:`~stat.S_IXOTH`)
+ if the owner doesn’t have it (:const:`~stat.S_IXUSR`).
- For other files (directories), set ``mode`` to ``None``, so
that extraction methods skip applying permission bits.
`SetErrorMode <https://msdn.microsoft.com/en-us/library/windows/desktop/ms680621.aspx>`_.
On UNIX, :func:`resource.setrlimit` is used to set
- :attr:`resource.RLIMIT_CORE`'s soft limit to 0 to prevent coredump file
+ :const:`resource.RLIMIT_CORE`'s soft limit to 0 to prevent coredump file
creation.
On both platforms, the old value is restored by :meth:`__exit__`.
interpreter and calls :func:`exec` on the contents of
:file:`.{className}.py` and :file:`.{baseName}.py`. The path for the
profile files is the :envvar:`HOME` environment variable or, if that
- isn't defined, then :attr:`os.curdir`.
+ isn't defined, then :data:`os.curdir`.
.. attribute:: tk
If given, *level* should be either a numeric logging level or
its string equivalent (for example either ``"ERROR"`` or
- :attr:`logging.ERROR`). The default is :attr:`logging.INFO`.
+ :const:`logging.ERROR`). The default is :const:`logging.INFO`.
The test passes if at least one message emitted inside the ``with``
block matches the *logger* and *level* conditions, otherwise it fails.
If given, *level* should be either a numeric logging level or
its string equivalent (for example either ``"ERROR"`` or
- :attr:`logging.ERROR`). The default is :attr:`logging.INFO`.
+ :const:`logging.ERROR`). The default is :const:`logging.INFO`.
Unlike :meth:`assertLogs`, nothing will be returned by the context
manager.
.. impl-detail::
- In CPython, the length is required to be at most :attr:`sys.maxsize`.
- If the length is larger than :attr:`!sys.maxsize` some features (such as
+ In CPython, the length is required to be at most :data:`sys.maxsize`.
+ If the length is larger than :data:`!sys.maxsize` some features (such as
:func:`len`) may raise :exc:`OverflowError`. To prevent raising
:exc:`!OverflowError` by truth value testing, an object must define a
:meth:`__bool__` method.
Modules specified in the registry under ``Modules`` (not ``PythonPath``)
may be imported by :class:`importlib.machinery.WindowsRegistryFinder`.
This finder is enabled on Windows in 3.6.0 and earlier, but may need to
- be explicitly added to :attr:`sys.meta_path` in the future.
+ be explicitly added to :data:`sys.meta_path` in the future.
Additional modules
==================
return times that are precise to fractions of a second; not all systems support
such precision.)
- Constants named :attr:`os.SEEK_SET`, :attr:`os.SEEK_CUR`, and
- :attr:`os.SEEK_END` have been added; these are the parameters to the
+ Constants named :const:`os.SEEK_SET`, :const:`os.SEEK_CUR`, and
+ :const:`os.SEEK_END` have been added; these are the parameters to the
:func:`os.lseek` function. Two new constants for locking are
- :attr:`os.O_SHLOCK` and :attr:`os.O_EXLOCK`.
+ :const:`os.O_SHLOCK` and :const:`os.O_EXLOCK`.
Two new functions, :func:`wait3` and :func:`wait4`, were added. They're similar
the :func:`waitpid` function which waits for a child process to exit and returns
* The :mod:`unicodedata` module has been updated to use version 4.1.0 of the
Unicode character database. Version 3.2.0 is required by some specifications,
- so it's still available as :attr:`unicodedata.ucd_3_2_0`.
+ so it's still available as :data:`unicodedata.ucd_3_2_0`.
* New module: the :mod:`uuid` module generates universally unique identifiers
(UUIDs) according to :rfc:`4122`. The RFC defines several different UUID
* The :mod:`io` module has three new constants for the :meth:`seek`
method :data:`SEEK_SET`, :data:`SEEK_CUR`, and :data:`SEEK_END`.
-* The :attr:`sys.version_info` tuple is now a named tuple::
+* The :data:`sys.version_info` tuple is now a named tuple::
>>> sys.version_info
sys.version_info(major=3, minor=1, micro=0, releaselevel='alpha', serial=2)
Apart from the performance improvements this change should be invisible to
end users, with one exception: for testing and debugging purposes there's a
- new :attr:`sys.int_info` that provides information about the
+ new :data:`sys.int_info` that provides information about the
internal format, giving the number of bits per digit and the size in bytes
of the C type used to store each digit::
datetime
--------
-* Add :attr:`datetime.UTC`, a convenience alias for
+* Add :const:`datetime.UTC`, a convenience alias for
:attr:`datetime.timezone.utc`. (Contributed by Kabir Kwatra in :gh:`91973`.)
* :meth:`datetime.date.fromisoformat`, :meth:`datetime.time.fromisoformat` and
even though the underlying platform may have a different convention. To bridge
this gap, the :mod:`wsgiref` module has a new function,
:func:`wsgiref.handlers.read_environ` for transcoding CGI variables from
-:attr:`os.environ` into native strings and returning a new dictionary.
+:data:`os.environ` into native strings and returning a new dictionary.
.. seealso::
* The interpreter can now be started with a quiet option, ``-q``, to prevent
the copyright and version information from being displayed in the interactive
- mode. The option can be introspected using the :attr:`sys.flags` attribute:
+ mode. The option can be introspected using the :data:`sys.flags` attribute:
.. code-block:: shell-session
* The internal :c:type:`structsequence` tool now creates subclasses of tuple.
This means that C structures like those returned by :func:`os.stat`,
- :func:`time.gmtime`, and :attr:`sys.version_info` now work like a
+ :func:`time.gmtime`, and :data:`sys.version_info` now work like a
:term:`named tuple` and now work with functions and methods that
expect a tuple as an argument. This is a big step forward in making the C
structures as flexible as their pure Python counterparts:
module, or on the command line.
A :exc:`ResourceWarning` is issued at interpreter shutdown if the
- :data:`gc.garbage` list isn't empty, and if :attr:`gc.DEBUG_UNCOLLECTABLE` is
+ :data:`gc.garbage` list isn't empty, and if :const:`gc.DEBUG_UNCOLLECTABLE` is
set, all uncollectable objects are printed. This is meant to make the
programmer aware that their code contains object finalization issues.
:class:`collections.Sequence` :term:`abstract base class`. As a result, the
language will have a more uniform API. In addition, :class:`range` objects
now support slicing and negative indices, even with values larger than
- :attr:`sys.maxsize`. This makes *range* more interoperable with lists::
+ :data:`sys.maxsize`. This makes *range* more interoperable with lists::
>>> range(0, 100, 2).count(10)
1
after 1900. The new supported year range is from 1000 to 9999 inclusive.
* Whenever a two-digit year is used in a time tuple, the interpretation has been
- governed by :attr:`time.accept2dyear`. The default is ``True`` which means that
+ governed by :data:`time.accept2dyear`. The default is ``True`` which means that
for a two-digit year, the century is guessed according to the POSIX rules
governing the ``%y`` strptime format.
Starting with Py3.2, use of the century guessing heuristic will emit a
:exc:`DeprecationWarning`. Instead, it is recommended that
- :attr:`time.accept2dyear` be set to ``False`` so that large date ranges
+ :data:`time.accept2dyear` be set to ``False`` so that large date ranges
can be used without guesswork::
>>> import time, warnings
'Fri Jan 1 12:34:56 11'
Several functions now have significantly expanded date ranges. When
- :attr:`time.accept2dyear` is false, the :func:`time.asctime` function will
+ :data:`time.accept2dyear` is false, the :func:`time.asctime` function will
accept any year that fits in a C int, while the :func:`time.mktime` and
:func:`time.strftime` functions will accept the full range supported by the
corresponding operating system functions.
If no configuration is set-up before a logging event occurs, there is now a
default configuration using a :class:`~logging.StreamHandler` directed to
-:attr:`sys.stderr` for events of ``WARNING`` level or higher. Formerly, an
+:data:`sys.stderr` for events of ``WARNING`` level or higher. Formerly, an
event occurring before a configuration was set-up would either raise an
exception or silently drop the event depending on the value of
-:attr:`logging.raiseExceptions`. The new default handler is stored in
-:attr:`logging.lastResort`.
+:data:`logging.raiseExceptions`. The new default handler is stored in
+:data:`logging.lastResort`.
The use of filters has been simplified. Instead of creating a
:class:`~logging.Filter` object, the predicate can be any Python callable that
hash(Decimal("1.5")) == hash(complex(1.5, 0))
Some of the hashing details are exposed through a new attribute,
-:attr:`sys.hash_info`, which describes the bit width of the hash value, the
+:data:`sys.hash_info`, which describes the bit width of the hash value, the
prime modulus, the hash values for *infinity* and *nan*, and the multiplier
used for the imaginary part of a number:
------
The :mod:`select` module now exposes a new, constant attribute,
-:attr:`~select.PIPE_BUF`, which gives the minimum number of bytes which are
+:const:`~select.PIPE_BUF`, which gives the minimum number of bytes which are
guaranteed not to block when :func:`select.select` says a pipe is ready
for writing.
b'Sehensw\xc3\xbcrdigkeiten'
Some operating systems allow direct access to encoded bytes in the
-environment. If so, the :attr:`os.supports_bytes_environ` constant will be
+environment. If so, the :const:`os.supports_bytes_environ` constant will be
true.
For direct access to encoded environment variables (if available),
The demonstration code for the :mod:`turtle` module was moved from the *Demo*
directory to main library. It includes over a dozen sample scripts with
-lively displays. Being on :attr:`sys.path`, it can now be run directly
+lively displays. Being on :data:`sys.path`, it can now be run directly
from the command-line:
.. code-block:: shell-session
(:issue:`2443`).
* A new C API function :c:func:`PySys_SetArgvEx` allows an embedded interpreter
- to set :attr:`sys.argv` without also modifying :attr:`sys.path`
+ to set :data:`sys.argv` without also modifying :data:`sys.path`
(:issue:`5753`).
* :c:macro:`PyEval_CallObject` is now only available in macro form. The
A new attribute on the :mod:`sys` module exposes details specific to the
implementation of the currently running interpreter. The initial set of
-attributes on :attr:`sys.implementation` are ``name``, ``version``,
+attributes on :data:`sys.implementation` are ``name``, ``version``,
``hexversion``, and ``cache_tag``.
The intention of ``sys.implementation`` is to consolidate into one namespace
In terms of finders, :class:`importlib.machinery.FileFinder` exposes the
mechanism used to search for source and bytecode files of a module. Previously
-this class was an implicit member of :attr:`sys.path_hooks`.
+this class was an implicit member of :data:`sys.path_hooks`.
For loaders, the new abstract base class :class:`importlib.abc.FileLoader` helps
write a loader that uses the file system as the storage mechanism for a module's
module's name.
The :func:`importlib.invalidate_caches` function will now call the method with
-the same name on all finders cached in :attr:`sys.path_importer_cache` to help
+the same name on all finders cached in :data:`sys.path_importer_cache` to help
clean up any stored state as necessary.
Visible Changes
section.
Beyond the expanse of what :mod:`importlib` now exposes, there are other
-visible changes to import. The biggest is that :attr:`sys.meta_path` and
-:attr:`sys.path_hooks` now store all of the meta path finders and path entry
+visible changes to import. The biggest is that :data:`sys.meta_path` and
+:data:`sys.path_hooks` now store all of the meta path finders and path entry
hooks used by import. Previously the finders were implicit and hidden within
the C code of import instead of being directly exposed. This means that one can
now easily remove or change the order of the various finders to fit one's needs.
:pep:`366`. Once again, import itself is already setting this on all loaders
from :mod:`importlib` and import itself is setting the attribute post-load.
-``None`` is now inserted into :attr:`sys.path_importer_cache` when no finder
-can be found on :attr:`sys.path_hooks`. Since :class:`imp.NullImporter` is not
-directly exposed on :attr:`sys.path_hooks` it could no longer be relied upon to
+``None`` is now inserted into :data:`sys.path_importer_cache` when no finder
+can be found on :data:`sys.path_hooks`. Since :class:`imp.NullImporter` is not
+directly exposed on :data:`sys.path_hooks` it could no longer be relied upon to
always be available to use as a value representing no finder found.
All other changes relate to semantic changes which should be taken into
* You can query the SSL compression algorithm used by an SSL socket, thanks
to its new :meth:`~ssl.SSLSocket.compression` method. The new attribute
- :attr:`~ssl.OP_NO_COMPRESSION` can be used to disable compression.
+ :const:`~ssl.OP_NO_COMPRESSION` can be used to disable compression.
(Contributed by Antoine Pitrou in :issue:`13634`.)
* Support has been added for the Next Protocol Negotiation extension using
* The :func:`~ssl.get_server_certificate` function now supports IPv6.
(Contributed by Charles-François Natali in :issue:`11811`.)
-* New attribute :attr:`~ssl.OP_CIPHER_SERVER_PREFERENCE` allows setting
+* New attribute :const:`~ssl.OP_CIPHER_SERVER_PREFERENCE` allows setting
SSLv3 server sockets to use the server's cipher ordering preference rather
than the client's (:issue:`13635`).
between a properly formed compressed stream and an incomplete or truncated one.
(Contributed by Nadeem Vawda in :issue:`12646`.)
-New attribute :attr:`zlib.ZLIB_RUNTIME_VERSION` reports the version string of
+New attribute :const:`zlib.ZLIB_RUNTIME_VERSION` reports the version string of
the underlying ``zlib`` library that is loaded at runtime. (Contributed by
Torsten Landschoff in :issue:`12306`.)
* :func:`__import__` no longer allows one to use an index value other than 0
for top-level modules. E.g. ``__import__('sys', level=1)`` is now an error.
-* Because :attr:`sys.meta_path` and :attr:`sys.path_hooks` now have finders on
+* Because :data:`sys.meta_path` and :data:`sys.path_hooks` now have finders on
them by default, you will most likely want to use :meth:`list.insert` instead
of :meth:`list.append` to add to those lists.
-* Because ``None`` is now inserted into :attr:`sys.path_importer_cache`, if you
+* Because ``None`` is now inserted into :data:`sys.path_importer_cache`, if you
are clearing out entries in the dictionary of paths that do not have a
finder, you will need to remove keys paired with values of ``None`` **and**
:class:`imp.NullImporter` to be backwards-compatible. This will lead to extra
overhead on older versions of Python that re-insert ``None`` into
- :attr:`sys.path_importer_cache` where it represents the use of implicit
+ :data:`sys.path_importer_cache` where it represents the use of implicit
finders, but semantically it should not change anything.
* :class:`importlib.abc.Finder` no longer specifies a ``find_module()`` abstract
error instead of sleeping forever. It has always raised an error on posix.
* The ``ast.__version__`` constant has been removed. If you need to
- make decisions affected by the AST version, use :attr:`sys.version_info`
+ make decisions affected by the AST version, use :data:`sys.version_info`
to make the decision.
* Code that used to work around the fact that the :mod:`threading` module used
making the call. (Contributed by Christian Heimes in :issue:`16595`.)
On Linux kernel version 2.6.36 or later, there are also some new
-Linux specific constants: :attr:`~resource.RLIMIT_MSGQUEUE`,
-:attr:`~resource.RLIMIT_NICE`, :attr:`~resource.RLIMIT_RTPRIO`,
-:attr:`~resource.RLIMIT_RTTIME`, and :attr:`~resource.RLIMIT_SIGPENDING`.
+Linux specific constants: :const:`~resource.RLIMIT_MSGQUEUE`,
+:const:`~resource.RLIMIT_NICE`, :const:`~resource.RLIMIT_RTPRIO`,
+:const:`~resource.RLIMIT_RTTIME`, and :const:`~resource.RLIMIT_SIGPENDING`.
(Contributed by Christian Heimes in :issue:`19324`.)
On FreeBSD version 9 and later, there some new FreeBSD specific constants:
-:attr:`~resource.RLIMIT_SBSIZE`, :attr:`~resource.RLIMIT_SWAP`, and
-:attr:`~resource.RLIMIT_NPTS`. (Contributed by Claudiu Popa in
+:const:`~resource.RLIMIT_SBSIZE`, :const:`~resource.RLIMIT_SWAP`, and
+:const:`~resource.RLIMIT_NPTS`. (Contributed by Claudiu Popa in
:issue:`19343`.)
are platform-dependent. (Contributed by Christian Heimes in :issue:`11016`.)
The module supports new :mod:`~stat.ST_MODE` flags, :mod:`~stat.S_IFDOOR`,
-:attr:`~stat.S_IFPORT`, and :attr:`~stat.S_IFWHT`. (Contributed by
+:const:`~stat.S_IFPORT`, and :const:`~stat.S_IFWHT`. (Contributed by
Christian Hiemes in :issue:`11016`.)
have a 64 bit data type. Any performance differences in comparison with the
older FNV algorithm are trivial.
-The PEP adds additional fields to the :attr:`sys.hash_info` named tuple to
+The PEP adds additional fields to the :data:`sys.hash_info` named tuple to
describe the hash algorithm in use by the currently executing binary. Otherwise,
the PEP does not alter any existing CPython APIs.
site
----
-When specifying paths to add to :attr:`sys.path` in a ``.pth`` file,
+When specifying paths to add to :data:`sys.path` in a ``.pth`` file,
you may now specify file paths on top of directories (e.g. zip files).
(Contributed by Wolfgang Langner in :issue:`26587`).
:meth:`importlib.abc.Loader.exec_module`.
The :class:`importlib.machinery.WindowsRegistryFinder` class is now
-deprecated. As of 3.6.0, it is still added to :attr:`sys.meta_path` by
+deprecated. As of 3.6.0, it is still added to :data:`sys.meta_path` by
default (on Windows), but this may change in future releases.
os
classes will affect their string representation.
(Contributed by Serhiy Storchaka in :issue:`36793`.)
-* On AIX, :attr:`sys.platform` doesn't contain the major version anymore.
+* On AIX, :data:`sys.platform` doesn't contain the major version anymore.
It is always ``'aix'``, instead of ``'aix3'`` .. ``'aix7'``. Since
older Python versions include the version number, so it is recommended to
always use ``sys.platform.startswith('aix')``.
sys
---
-Added a new :attr:`sys.platlibdir` attribute: name of the platform-specific
+Added a new :data:`sys.platlibdir` attribute: name of the platform-specific
library directory. It is used to build the path of standard library and the
paths of installed extension modules. It is equal to ``"lib"`` on most
platforms. On Fedora and SuSE, it is equal to ``"lib64"`` on 64-bit platforms.
(Contributed by Jan Matějek, Matěj Cepl, Charalampos Stratakis and Victor Stinner in :issue:`1294959`.)
-Previously, :attr:`sys.stderr` was block-buffered when non-interactive. Now
+Previously, :data:`sys.stderr` was block-buffered when non-interactive. Now
``stderr`` defaults to always being line-buffered.
(Contributed by Jendrik Seipp in :issue:`13601`.)
=============
* Added ``--with-platlibdir`` option to the ``configure`` script: name of the
- platform-specific library directory, stored in the new :attr:`sys.platlibdir`
- attribute. See :attr:`sys.platlibdir` attribute for more information.
+ platform-specific library directory, stored in the new :data:`sys.platlibdir`
+ attribute. See :data:`sys.platlibdir` attribute for more information.
(Contributed by Jan Matějek, Matěj Cepl, Charalampos Stratakis
and Victor Stinner in :issue:`1294959`.)
.. nonce: wejLoC
.. section: Core and Builtins
-On AIX, :attr:`sys.platform` doesn't contain the major version anymore.
+On AIX, :data:`sys.platform` doesn't contain the major version anymore.
Always return ``'aix'``, instead of ``'aix3'`` .. ``'aix7'``. Since older
Python versions include the version number, it is recommended to always use
``sys.platform.startswith('aix')``. Contributed by M. Felt.
Avoid a possible *"RuntimeError: dictionary changed size during iteration"*
from :func:`inspect.getmodule` when it tried to loop through
-:attr:`sys.modules`.
+:data:`sys.modules`.
..
Add ``--with-platlibdir`` option to the configure script: name of the
platform-specific library directory, stored in the new
-:attr:`sys.platlibdir` attribute. It is used to build the path of
+:data:`sys.platlibdir` attribute. It is used to build the path of
platform-specific extension modules and the path of the standard library. It
is equal to ``"lib"`` on most platforms. On Fedora and SuSE, it is equal to
``"lib64"`` on 64-bit platforms. Patch by Jan Matějek, Matěj Cepl,