2019-05-20 16:15:35 -04:00
|
|
|
|
PEP: 594
|
|
|
|
|
Title: Removing dead batteries from the standard library
|
2022-01-25 17:51:26 -05:00
|
|
|
|
Author: Christian Heimes <christian@python.org>,
|
|
|
|
|
Brett Cannon <brett@python.org>
|
2019-05-22 07:32:12 -04:00
|
|
|
|
Discussions-To: https://discuss.python.org/t/pep-594-removing-dead-batteries-from-the-standard-library/1704
|
2019-05-20 18:07:23 -04:00
|
|
|
|
Status: Draft
|
|
|
|
|
Type: Standards Track
|
2019-05-20 16:15:35 -04:00
|
|
|
|
Content-Type: text/x-rst
|
|
|
|
|
Created: 20-May-2019
|
2022-01-25 17:51:26 -05:00
|
|
|
|
Python-Version: 3.11
|
2019-05-21 07:05:45 -04:00
|
|
|
|
Post-History: 21-May-2019
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Abstract
|
|
|
|
|
========
|
|
|
|
|
|
|
|
|
|
This PEP proposed a list of standard library modules to be removed from the
|
2019-05-28 01:51:25 -04:00
|
|
|
|
standard library. The modules are mostly historic data formats (e.g. Commodore
|
|
|
|
|
and SUN file formats), APIs and operating systems that have been superseded a
|
|
|
|
|
long time ago (e.g. Mac OS 9), or modules that have security implications and
|
|
|
|
|
better alternatives (e.g. password and login).
|
|
|
|
|
|
2022-01-25 17:51:26 -05:00
|
|
|
|
The PEP follows in the footsteps of other PEPS like :pep:`3108`. The
|
2019-05-28 01:51:25 -04:00
|
|
|
|
*Standard Library Reorganization* proposal removed a bunch of modules from
|
|
|
|
|
Python 3.0. In 2007, the PEP referred to maintenance burden as:
|
|
|
|
|
|
|
|
|
|
"Over the years, certain modules have become a heavy burden upon python-dev
|
|
|
|
|
to maintain. In situations like this, it is better for the module to be
|
|
|
|
|
given to the community to maintain to free python-dev to focus more on
|
|
|
|
|
language support and other modules in the standard library that do not take
|
|
|
|
|
up an undue amount of time and effort."
|
|
|
|
|
|
|
|
|
|
The withdrawn :pep:`206` from 2000 expresses issues with the Python standard
|
2022-01-25 17:51:26 -05:00
|
|
|
|
library in an unvarnished and forthright manner:
|
2019-05-28 01:51:25 -04:00
|
|
|
|
|
|
|
|
|
"[...] the standard library modules aren't always the best choices for a
|
|
|
|
|
job. Some library modules were quick hacks (e.g. ``calendar``,
|
|
|
|
|
``commands``), some were designed poorly and are now near-impossible to
|
|
|
|
|
fix (``cgi``), and some have been rendered obsolete by other, more complete
|
|
|
|
|
modules [...]."
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Rationale
|
|
|
|
|
=========
|
|
|
|
|
|
|
|
|
|
Back in the early days of Python, the interpreter came with a large set of
|
2019-05-26 03:19:05 -04:00
|
|
|
|
useful modules. This was often referred to as "batteries included"
|
2019-06-03 06:29:54 -04:00
|
|
|
|
philosophy and was one of the cornerstones to Python's success story.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
Users didn't have to figure out how to download and install separate
|
|
|
|
|
packages in order to write a simple web server or parse email.
|
|
|
|
|
|
2022-01-25 17:51:26 -05:00
|
|
|
|
Times have changed. The introduction of PyPI (née Cheeseshop), setuptools,
|
2019-06-03 06:29:54 -04:00
|
|
|
|
and later pip, it became simple and straightforward to download and install
|
|
|
|
|
packages. Nowadays Python has a rich and vibrant ecosystem of third-party
|
2019-05-20 16:15:35 -04:00
|
|
|
|
packages. It's pretty much standard to either install packages from PyPI or
|
|
|
|
|
use one of the many Python or Linux distributions.
|
|
|
|
|
|
2022-01-25 17:51:26 -05:00
|
|
|
|
On the other hand, Python's standard library is piling up with cruft, unnecessary
|
2019-05-20 16:15:35 -04:00
|
|
|
|
duplication of functionality, and dispensable features. This is undesirable
|
|
|
|
|
for several reasons.
|
|
|
|
|
|
|
|
|
|
* Any additional module increases the maintenance cost for the Python core
|
|
|
|
|
development team. The team has limited resources, reduced maintenance cost
|
|
|
|
|
frees development time for other improvements.
|
|
|
|
|
* Modules in the standard library are generally favored and seen as the
|
2021-02-03 09:06:23 -05:00
|
|
|
|
de facto solution for a problem. A majority of users only pick third-party
|
2019-05-20 16:15:35 -04:00
|
|
|
|
modules to replace a stdlib module, when they have a compelling reason, e.g.
|
2019-06-03 06:29:54 -04:00
|
|
|
|
``lxml`` instead of ``xml``. The removal of an unmaintained stdlib module
|
|
|
|
|
increases the chances of a community-contributed module to become widely
|
2019-05-20 16:15:35 -04:00
|
|
|
|
used.
|
|
|
|
|
* A lean and mean standard library benefits platforms with limited resources
|
|
|
|
|
like devices with just a few hundred kilobyte of storage (e.g. BBC
|
|
|
|
|
Micro:bit). Python on mobile platforms like BeeWare or WebAssembly
|
|
|
|
|
(e.g. pyodide) also benefit from reduced download size.
|
|
|
|
|
|
2022-01-25 17:51:26 -05:00
|
|
|
|
The modules in this PEP have been selected for deprecation because their
|
2019-06-03 06:29:54 -04:00
|
|
|
|
removal is either least controversial or most beneficial. For example,
|
|
|
|
|
least controversial are 30-year-old multimedia formats like the ``sunau``
|
2019-05-20 16:15:35 -04:00
|
|
|
|
audio format, which was used on SPARC and NeXT workstations in the late
|
2019-06-03 06:29:54 -04:00
|
|
|
|
1980s. The ``crypt`` module has fundamental flaws that are better solved
|
2019-05-20 16:15:35 -04:00
|
|
|
|
outside the standard library.
|
|
|
|
|
|
|
|
|
|
This PEP also designates some modules as not scheduled for removal. Some
|
|
|
|
|
modules have been deprecated for several releases or seem unnecessary at
|
|
|
|
|
first glance. However it is beneficial to keep the modules in the standard
|
|
|
|
|
library, mostly for environments where installing a package from PyPI is not
|
2019-06-03 06:29:54 -04:00
|
|
|
|
an option. This can be corporate environments or classrooms where external
|
2019-05-20 16:15:35 -04:00
|
|
|
|
code is not permitted without legal approval.
|
|
|
|
|
|
|
|
|
|
* The usage of FTP is declining, but some files are still provided over
|
2021-02-03 09:06:23 -05:00
|
|
|
|
the FTP protocol or hosters offer FTP to upload content. Therefore,
|
2019-05-20 16:15:35 -04:00
|
|
|
|
``ftplib`` is going to stay.
|
2019-06-03 06:29:54 -04:00
|
|
|
|
* The ``optparse`` and ``getopt`` modules are widely used. They are mature
|
2019-05-20 16:15:35 -04:00
|
|
|
|
modules with very low maintenance overhead.
|
|
|
|
|
* According to David Beazley [5]_ the ``wave`` module is easy to teach to
|
2022-01-25 17:51:26 -05:00
|
|
|
|
kids and can make crazy sounds. Making a computer generate sounds is a
|
2019-06-03 06:29:54 -04:00
|
|
|
|
powerful and highly motivating exercise for a nine-year-old aspiring developer.
|
|
|
|
|
It's a fun battery to keep.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Deprecation schedule
|
|
|
|
|
====================
|
|
|
|
|
|
2022-01-25 17:51:26 -05:00
|
|
|
|
3.11
|
2019-05-20 16:15:35 -04:00
|
|
|
|
----
|
|
|
|
|
|
2022-01-25 17:51:26 -05:00
|
|
|
|
Starting with Python 3.11, deprecated modules will start issuing
|
2022-02-01 17:32:55 -05:00
|
|
|
|
``DeprecationWarning``. The estimated EOL of Python 3.10, the last
|
|
|
|
|
version without the warning, is October 2026.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
2022-01-25 17:51:26 -05:00
|
|
|
|
3.12
|
|
|
|
|
----
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
2022-01-25 17:51:26 -05:00
|
|
|
|
There should be no specific change compared to Python 3.11.
|
2022-02-01 17:32:55 -05:00
|
|
|
|
This is the last version of Python with the deprecated modules,
|
|
|
|
|
with an estimated EOL of October 2028.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
2022-01-25 17:51:26 -05:00
|
|
|
|
3.13
|
|
|
|
|
----
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
2022-01-25 17:51:26 -05:00
|
|
|
|
All modules deprecated by this PEP are removed from the ``main`` branch
|
|
|
|
|
of the CPython repository and are no longer distributed as part of Python.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Deprecated modules
|
|
|
|
|
==================
|
|
|
|
|
|
|
|
|
|
The modules are grouped as data encoding, multimedia, network, OS interface,
|
|
|
|
|
and misc modules. The majority of modules are for old data formats or
|
|
|
|
|
old APIs. Some others are rarely useful and have better replacements on
|
|
|
|
|
PyPI, e.g. Pillow for image processing or NumPy-based projects to deal with
|
|
|
|
|
audio processing.
|
|
|
|
|
|
|
|
|
|
.. csv-table:: Table 1: Proposed modules deprecations
|
2019-05-28 01:51:25 -04:00
|
|
|
|
:header: "Module", "Deprecated in", "To be removed", "Added in", "Has maintainer?", "Replacement"
|
|
|
|
|
:widths: 2, 1, 1, 1, 1, 2
|
|
|
|
|
|
2022-01-25 17:51:26 -05:00
|
|
|
|
aifc,3.11 (3.0\*),3.13,1993,**yes (inactive)**,\-
|
|
|
|
|
asynchat,**3.6** (3.0\*),3.12,1999,**yes**,asyncio_
|
|
|
|
|
asyncore,**3.6** (3.0\*),3.12,1999,**yes**,asyncio_
|
|
|
|
|
audioop,3.11 (3.0\*),3.13,1992,**yes**,\-
|
|
|
|
|
cgi,3.11 (2.0\*\*),3.13,1995,no,\-
|
|
|
|
|
cgitb,3.11 (2.0\*\*),3.13,1995,no,\-
|
|
|
|
|
chunk,3.11,3.13,1999,no,\-
|
|
|
|
|
crypt,3.11,3.13,1994,**yes (inactive)**,"legacycrypt_, bcrypt_, argon2-cffi_, hashlib_, passlib_"
|
|
|
|
|
imghdr,3.11,3.13,1992,no,"filetype_, puremagic_, python-magic_"
|
|
|
|
|
msilib,3.11,3.13,2006,no,\-
|
|
|
|
|
nntplib,3.11,3.13,1992,no,\-
|
|
|
|
|
nis,3.8 (3.0\*),3.13,1992,no,\-
|
|
|
|
|
ossaudiodev,3.11,3.13,2002,no,\-
|
|
|
|
|
pipes,3.11,3.13,1992,no,"subprocess_"
|
|
|
|
|
smtpd,"**3.4.7**, **3.5.4**",3.12,2001,**yes**,"aiosmtpd_"
|
|
|
|
|
sndhdr,3.11,3.13,1994,no,"filetype_, puremagic_, python-magic_"
|
|
|
|
|
spwd,3.11,3.13,2005,no,"python-pam_"
|
|
|
|
|
sunau,3.11 (3.0\*),3.13,1993,no,\-
|
|
|
|
|
telnetlib,3.11 (3.0\*),3.13,1997,no,"telnetlib3_, Exscript_"
|
|
|
|
|
uu,3.11,3.13,1994,no,\-
|
|
|
|
|
xdrlib,3.11,3.13,1992/1996,no,\-
|
2019-05-28 01:51:25 -04:00
|
|
|
|
|
2020-10-22 19:17:50 -04:00
|
|
|
|
.. _aiosmtpd: https://pypi.org/project/aiosmtpd/
|
2022-01-25 17:51:26 -05:00
|
|
|
|
.. _argon2-cffi: https://pypi.org/project/argon2-cffi/
|
2020-10-22 19:17:50 -04:00
|
|
|
|
.. _ast: https://docs.python.org/3/library/ast.html
|
|
|
|
|
.. _astroid: https://pypi.org/project/astroid/
|
|
|
|
|
.. _asyncio: https://docs.python.org/3/library/hashlib.html
|
|
|
|
|
.. _bcrypt: https://pypi.org/project/bcrypt/
|
|
|
|
|
.. _Exscript: https://pypi.org/project/Exscript/
|
|
|
|
|
.. _filetype: https://pypi.org/project/filetype/
|
|
|
|
|
.. _hashlib: https://docs.python.org/3/library/hashlib.html
|
|
|
|
|
.. _importlib: https://docs.python.org/3/library/importlib.html
|
|
|
|
|
.. _legacycrypt: https://pypi.org/project/legacycrypt/
|
|
|
|
|
.. _passlib: https://pypi.org/project/passlib/
|
|
|
|
|
.. _puremagic: https://pypi.org/project/puremagic/
|
|
|
|
|
.. _python-magic: https://pypi.org/project/python-magic/
|
|
|
|
|
.. _python-pam: https://pypi.org/project/python-pam/
|
|
|
|
|
.. _simplepam: https://pypi.org/project/simplepam/
|
|
|
|
|
.. _subprocess: https://docs.python.org/3/library/subprocess.html
|
|
|
|
|
.. _telnetlib3: https://pypi.org/project/telnetlib3/
|
|
|
|
|
|
2019-05-28 01:51:25 -04:00
|
|
|
|
Some module deprecations proposed by :pep:`3108` for 3.0 and :pep:`206` for
|
|
|
|
|
2.0. The *added in* column illustrates, when a module was originally designed
|
2021-02-03 09:06:23 -05:00
|
|
|
|
and added to the standard library. The *has maintainer* column refers to the
|
2019-05-28 01:51:25 -04:00
|
|
|
|
`expert index <https://devguide.python.org/experts/>`_, a list of domain
|
|
|
|
|
experts and maintainers in the DevGuide.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Data encoding modules
|
|
|
|
|
---------------------
|
|
|
|
|
|
|
|
|
|
|
2020-02-24 23:33:49 -05:00
|
|
|
|
uu and the uu encoding
|
|
|
|
|
~~~~~~~~~~~~~~~~~~~~~~
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
The `uu <https://docs.python.org/3/library/uu.html>`_ module provides
|
|
|
|
|
uuencode format, an old binary encoding format for email from 1980. The uu
|
2019-06-03 06:29:54 -04:00
|
|
|
|
format has been replaced by MIME. The uu codec is provided by the ``binascii``
|
2020-02-24 23:33:49 -05:00
|
|
|
|
module. There's also ``encodings/uu_codec.py`` which is a codec for the
|
|
|
|
|
same encoding; it should also be deprecated.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
xdrlib
|
|
|
|
|
~~~~~~
|
|
|
|
|
|
|
|
|
|
The `xdrlib <https://docs.python.org/3/library/xdrlib.html>`_ module supports
|
|
|
|
|
the Sun External Data Representation Standard. XDR is an old binary
|
|
|
|
|
serialization format from 1987. These days it's rarely used outside
|
|
|
|
|
specialized domains like NFS.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Multimedia modules
|
|
|
|
|
------------------
|
|
|
|
|
|
|
|
|
|
aifc
|
|
|
|
|
~~~~
|
|
|
|
|
|
|
|
|
|
The `aifc <https://docs.python.org/3/library/aifc.html>`_ module provides
|
|
|
|
|
support for reading and writing AIFF and AIFF-C files. The Audio Interchange
|
|
|
|
|
File Format is an old audio format from 1988 based on Amiga IFF. It was most
|
|
|
|
|
commonly used on the Apple Macintosh. These days only few specialized
|
|
|
|
|
application use AIFF.
|
|
|
|
|
|
2022-02-07 19:50:53 -05:00
|
|
|
|
A user disclosed [6]_ that the post production film industry makes heavy
|
2019-05-28 01:51:25 -04:00
|
|
|
|
use of the AIFC file format. The usage of the ``aifc`` module in closed source
|
|
|
|
|
and internal software was unknown prior to the first posting of this PEP. This
|
|
|
|
|
may be a compelling argument to keep the ``aifc`` module in the standard
|
|
|
|
|
library. The file format is stable and the module does not require much
|
|
|
|
|
maintenance. The strategic benefits for Python may outmatch the burden.
|
|
|
|
|
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
audioop
|
|
|
|
|
~~~~~~~
|
|
|
|
|
|
|
|
|
|
The `audioop <https://docs.python.org/3/library/audioop.html>`_ module
|
|
|
|
|
contains helper functions to manipulate raw audio data and adaptive
|
|
|
|
|
differential pulse-code modulated audio data. The module is implemented in
|
|
|
|
|
C without any additional dependencies. The `aifc`_, `sunau`_, and `wave`_
|
2019-06-03 06:29:54 -04:00
|
|
|
|
modules depend on `audioop`_ for some operations.
|
2019-05-28 01:51:25 -04:00
|
|
|
|
|
|
|
|
|
The byteswap operation in the ``wave`` module can be substituted with little
|
|
|
|
|
extra work. In case ``aifc`` is not deprecated as well, a reduced version of
|
|
|
|
|
the ``audioop`` module is converted into a private implementation detail,
|
|
|
|
|
e.g. ``_audioop`` with ``byteswap``, ``alaw2lin``, ``ulaw2lin``, ``lin2alaw``,
|
|
|
|
|
``lin2ulaw``, and ``lin2adpcm``.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
chunk
|
|
|
|
|
~~~~~
|
|
|
|
|
|
|
|
|
|
The `chunk <https://docs.python.org/3/library/chunk.html>`_ module provides
|
|
|
|
|
support for reading and writing Electronic Arts' Interchange File Format.
|
|
|
|
|
IFF is an old audio file format originally introduced for Commodore and
|
|
|
|
|
Amiga. The format is no longer relevant.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
imghdr
|
|
|
|
|
~~~~~~
|
|
|
|
|
|
|
|
|
|
The `imghdr <https://docs.python.org/3/library/imghdr.html>`_ module is a
|
|
|
|
|
simple tool to guess the image file format from the first 32 bytes
|
2019-06-03 06:29:54 -04:00
|
|
|
|
of a file or buffer. It supports only a limited number of formats and
|
2019-05-20 16:15:35 -04:00
|
|
|
|
neither returns resolution nor color depth.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
ossaudiodev
|
|
|
|
|
~~~~~~~~~~~
|
|
|
|
|
|
|
|
|
|
The `ossaudiodev <https://docs.python.org/3/library/ossaudiodev.html>`_
|
|
|
|
|
module provides support for Open Sound System, an interface to sound
|
|
|
|
|
playback and capture devices. OSS was initially free software, but later
|
|
|
|
|
support for newer sound devices and improvements were proprietary. Linux
|
|
|
|
|
community abandoned OSS in favor of ALSA [1]_. Some operation systems like
|
|
|
|
|
OpenBSD and NetBSD provide an incomplete [2]_ emulation of OSS.
|
|
|
|
|
|
2019-05-28 01:51:25 -04:00
|
|
|
|
To best of my knowledge, FreeBSD is the only widespread operating system
|
|
|
|
|
that uses Open Sound System as of today. The ``ossaudiodev`` hasn't seen any
|
|
|
|
|
improvements or new features since 2003. All commits since 2003 are
|
|
|
|
|
project-wide code cleanups and a couple of bug fixes. It would be beneficial
|
|
|
|
|
for both FreeBSD community and core development, if the module would be
|
|
|
|
|
maintained and distributed by people that care for it and use it.
|
|
|
|
|
|
|
|
|
|
The standard library used to have more audio-related modules. The other
|
|
|
|
|
audio device interface (``audiodev``, ``linuxaudiodev``, ``sunaudiodev``)
|
|
|
|
|
were removed in 2007 as part of the :pep:`3108` stdlib re-organization.
|
|
|
|
|
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
sndhdr
|
|
|
|
|
~~~~~~
|
|
|
|
|
|
|
|
|
|
The `sndhdr <https://docs.python.org/3/library/sndhdr.html>`_ module is
|
|
|
|
|
similar to the `imghdr`_ module but for audio formats. It guesses file
|
|
|
|
|
format, channels, frame rate, and sample widths from the first 512 bytes of
|
|
|
|
|
a file or buffer. The module only supports AU, AIFF, HCOM, VOC, WAV, and
|
|
|
|
|
other ancient formats.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
sunau
|
|
|
|
|
~~~~~
|
|
|
|
|
|
2022-02-07 14:30:56 -05:00
|
|
|
|
The `sunau <https://docs.python.org/3/library/sunau.html>`_ module provides
|
2019-05-20 16:15:35 -04:00
|
|
|
|
support for Sun AU sound format. It's yet another old, obsolete file format.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Networking modules
|
|
|
|
|
------------------
|
|
|
|
|
|
|
|
|
|
asynchat
|
|
|
|
|
~~~~~~~~
|
|
|
|
|
|
|
|
|
|
The `asynchat <https://docs.python.org/3/library/asynchat.html>`_ module
|
2019-06-03 06:29:54 -04:00
|
|
|
|
is built on top of `asyncore`_ and has been deprecated since Python 3.6.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
asyncore
|
|
|
|
|
~~~~~~~~
|
|
|
|
|
|
|
|
|
|
The `asyncore <https://docs.python.org/3/library/asyncore.html>`_ module was
|
|
|
|
|
the first module for asynchronous socket service clients and servers. It
|
|
|
|
|
has been replaced by asyncio and is deprecated since Python 3.6.
|
|
|
|
|
|
|
|
|
|
The ``asyncore`` module is also used in stdlib tests. The tests for
|
|
|
|
|
``ftplib``, ``logging``, ``smptd``, ``smtplib``, and ``ssl`` are partly
|
|
|
|
|
based on ``asyncore``. These tests must be updated to use asyncio or
|
|
|
|
|
threading.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
cgi
|
|
|
|
|
~~~
|
|
|
|
|
|
|
|
|
|
The `cgi <https://docs.python.org/3/library/cgi.html>`_ module is a support
|
|
|
|
|
module for Common Gateway Interface (CGI) scripts. CGI is deemed as
|
2019-05-28 01:51:25 -04:00
|
|
|
|
inefficient because every incoming request is handled in a new process.
|
|
|
|
|
:pep:`206` considers the module as:
|
|
|
|
|
|
|
|
|
|
"[...] designed poorly and are now near-impossible to fix (``cgi``) [...]"
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
2022-02-04 18:46:03 -05:00
|
|
|
|
Replacements for the various parts of ``cgi`` which are not directly
|
|
|
|
|
related to executing code are:
|
|
|
|
|
|
|
|
|
|
- ``parse`` with ``urllib.parse.parse_qs`` (``parse`` is just a wrapper)
|
|
|
|
|
- ``parse_header`` with ``email.message.Message`` (see example below)
|
|
|
|
|
- ``parse_multipart`` with ``email.message.Message`` (same MIME RFCs)
|
2022-02-07 19:50:09 -05:00
|
|
|
|
- ``FieldStorage``/``MiniFieldStorage`` has no direct replacement, but can
|
|
|
|
|
typically be replaced by using `multipart
|
|
|
|
|
<https://pypi.org/project/multipart/>`_ (for ``POST`` and ``PUT``
|
|
|
|
|
requests) or ``urllib.parse.parse_qsl`` (for ``GET`` and ``HEAD``
|
|
|
|
|
requests)
|
2022-02-04 18:46:03 -05:00
|
|
|
|
- ``valid_boundary`` (undocumented) with ``re.compile("^[ -~]{0,200}[!-~]$")``
|
|
|
|
|
|
|
|
|
|
As an explicit example of how close ``parse_header`` and
|
2022-02-07 19:50:53 -05:00
|
|
|
|
``email.message.Message`` are:
|
|
|
|
|
|
|
|
|
|
.. code-block:: pycon
|
2022-02-04 18:46:03 -05:00
|
|
|
|
|
|
|
|
|
>>> from cgi import parse_header
|
|
|
|
|
>>> from email.message import Message
|
|
|
|
|
>>> parse_header(h)
|
|
|
|
|
('application/json', {'charset': 'utf8'})
|
|
|
|
|
>>> m = Message()
|
|
|
|
|
>>> m['content-type'] = h
|
|
|
|
|
>>> m.get_params()
|
|
|
|
|
[('application/json', ''), ('charset', 'utf8')]
|
|
|
|
|
>>> m.get_param('charset')
|
|
|
|
|
'utf8'
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
cgitb
|
|
|
|
|
~~~~~
|
|
|
|
|
|
|
|
|
|
The `cgitb <https://docs.python.org/3/library/cgitb.html>`_ module is a
|
2019-06-03 06:29:54 -04:00
|
|
|
|
helper for the ``cgi`` module for configurable tracebacks.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
2019-05-21 07:05:45 -04:00
|
|
|
|
The ``cgitb`` module is not used by any major Python web framework (Django,
|
|
|
|
|
Pyramid, Plone, Flask, CherryPy, or Bottle). Only Paste uses it in an
|
|
|
|
|
optional debugging middleware.
|
|
|
|
|
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
smtpd
|
|
|
|
|
~~~~~
|
|
|
|
|
|
|
|
|
|
The `smtpd <https://docs.python.org/3/library/smtpd.html>`_ module provides
|
|
|
|
|
a simple implementation of a SMTP mail server. The module documentation
|
2019-05-21 07:05:45 -04:00
|
|
|
|
marks the module as deprecated and recommends ``aiosmtpd`` instead. The
|
|
|
|
|
deprecation message was added in releases 3.4.7, 3.5.4, and 3.6.1.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
nntplib
|
|
|
|
|
~~~~~~~
|
|
|
|
|
|
|
|
|
|
The `nntplib <https://docs.python.org/3/library/nntplib.html>`_ module
|
|
|
|
|
implements the client side of the Network News Transfer Protocol (nntp). News
|
|
|
|
|
groups used to be a dominant platform for online discussions. Over the last
|
|
|
|
|
two decades, news has been slowly but steadily replaced with mailing lists
|
2019-05-21 07:05:45 -04:00
|
|
|
|
and web-based discussion platforms. Twisted is also
|
|
|
|
|
`planning <https://twistedmatrix.com/trac/ticket/9405>`_ to deprecate NNTP
|
2019-05-26 03:17:46 -04:00
|
|
|
|
support and `pynntp <https://github.com/greenbender/pynntp>`_ hasn't seen any
|
2019-05-21 10:00:46 -04:00
|
|
|
|
activity since 2014. This is a good indicator that the public interest in
|
|
|
|
|
NNTP support is declining.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
The ``nntplib`` tests have been the cause of additional work in the recent
|
2019-05-21 07:05:45 -04:00
|
|
|
|
past. Python only contains client side of NNTP. The tests connect to
|
2019-05-26 03:16:48 -04:00
|
|
|
|
external news server. The servers are sometimes unavailable, too slow, or do
|
2019-05-21 07:05:45 -04:00
|
|
|
|
not work correctly over IPv6. The situation causes flaky test runs on
|
|
|
|
|
buildbots.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
2019-05-28 01:51:25 -04:00
|
|
|
|
telnetlib
|
|
|
|
|
~~~~~~~~~
|
|
|
|
|
|
|
|
|
|
The `telnetlib <https://docs.python.org/3/library/telnetlib.html>`_ module
|
|
|
|
|
provides a Telnet class that implements the Telnet protocol.
|
|
|
|
|
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
Operating system interface
|
|
|
|
|
--------------------------
|
|
|
|
|
|
|
|
|
|
crypt
|
|
|
|
|
~~~~~
|
|
|
|
|
|
|
|
|
|
The `crypt <https://docs.python.org/3/library/crypt.html>`_ module implements
|
2019-06-03 06:29:54 -04:00
|
|
|
|
password hashing based on the ``crypt(3)`` function from ``libcrypt`` or
|
|
|
|
|
``libxcrypt`` on Unix-like platforms. The algorithms are mostly old, of poor
|
2019-05-20 16:15:35 -04:00
|
|
|
|
quality and insecure. Users are discouraged to use them.
|
|
|
|
|
|
2019-06-03 06:29:54 -04:00
|
|
|
|
* The module is not available on Windows. Cross-platform applications need
|
|
|
|
|
an alternative implementation anyway.
|
2019-05-26 03:16:48 -04:00
|
|
|
|
* Only DES encryption is guaranteed to be available. DES has an extremely
|
2019-05-20 16:15:35 -04:00
|
|
|
|
limited key space of 2**56.
|
2019-06-03 06:29:54 -04:00
|
|
|
|
* MD5, salted SHA256, salted SHA512, and Blowfish are optional extensions.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
SSHA256 and SSHA512 are glibc extensions. Blowfish (bcrypt) is the only
|
|
|
|
|
algorithm that is still secure. However it's in glibc and therefore not
|
|
|
|
|
commonly available on Linux.
|
|
|
|
|
* Depending on the platform, the ``crypt`` module is not thread safe. Only
|
|
|
|
|
implementations with ``crypt_r(3)`` are thread safe.
|
2019-05-21 07:05:45 -04:00
|
|
|
|
* The module was never useful to interact with system user and password
|
|
|
|
|
databases. On BSD, macOS, and Linux, all user authentication and
|
|
|
|
|
password modification operations must go through PAM (pluggable
|
|
|
|
|
authentication module), see `spwd`_ deprecation.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
nis
|
|
|
|
|
~~~
|
|
|
|
|
|
|
|
|
|
The `nis <https://docs.python.org/3/library/nis.html>`_ module provides
|
|
|
|
|
NIS/YP support. Network Information Service / Yellow Pages is an old and
|
|
|
|
|
deprecated directory service protocol developed by Sun Microsystems. It's
|
|
|
|
|
designed successor NIS+ from 1992 never took off. For a long time, libc's
|
|
|
|
|
Name Service Switch, LDAP, and Kerberos/GSSAPI are considered a more powerful
|
|
|
|
|
and more secure replacement of NIS.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
spwd
|
|
|
|
|
~~~~
|
|
|
|
|
|
|
|
|
|
The `spwd <https://docs.python.org/3/library/spwd.html>`_ module provides
|
|
|
|
|
direct access to Unix shadow password database using non-standard APIs.
|
2019-05-21 07:05:45 -04:00
|
|
|
|
|
2019-06-03 06:29:54 -04:00
|
|
|
|
In general it's a bad idea to use spwd. It circumvents system
|
|
|
|
|
security policies, does not use the PAM stack, and is only compatible
|
2019-05-21 07:05:45 -04:00
|
|
|
|
with local user accounts, because it ignores NSS. The use of the ``spwd``
|
2019-06-03 06:29:54 -04:00
|
|
|
|
module for access control must be considered a *security bug*, as it bypasses
|
2019-05-21 07:05:45 -04:00
|
|
|
|
PAM's access control.
|
|
|
|
|
|
|
|
|
|
Further more the ``spwd`` module uses the
|
|
|
|
|
`shadow(3) <http://man7.org/linux/man-pages/man3/shadow.3.html>`_ APIs.
|
|
|
|
|
Functions like ``getspnam(3)`` access the ``/etc/shadow`` file directly. This
|
|
|
|
|
is dangerous and even forbidden for confined services on systems with a
|
|
|
|
|
security engine like SELinux or AppArmor.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Misc modules
|
|
|
|
|
------------
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
msilib
|
|
|
|
|
~~~~~~
|
|
|
|
|
|
|
|
|
|
The `msilib <https://docs.python.org/3/library/msilib.html>`_ package is a
|
|
|
|
|
Windows-only package. It supports the creation of Microsoft Installers (MSI).
|
|
|
|
|
The package also exposes additional APIs to create cabinet files (CAB). The
|
2019-06-03 06:29:54 -04:00
|
|
|
|
module is used to facilitate distutils to create MSI installers with the
|
2019-05-20 16:15:35 -04:00
|
|
|
|
``bdist_msi`` command. In the past it was used to create CPython's official
|
|
|
|
|
Windows installer, too.
|
|
|
|
|
|
|
|
|
|
Microsoft is slowly moving away from MSI in favor of Windows 10 Apps (AppX)
|
|
|
|
|
as new deployment model [3]_.
|
|
|
|
|
|
2019-05-21 07:05:45 -04:00
|
|
|
|
|
2019-05-20 16:15:35 -04:00
|
|
|
|
pipes
|
|
|
|
|
~~~~~
|
|
|
|
|
|
|
|
|
|
The `pipes <https://docs.python.org/3/library/pipes.html>`_ module provides
|
|
|
|
|
helpers to pipe the input of one command into the output of another command.
|
|
|
|
|
The module is built on top of ``os.popen``. Users are encouraged to use
|
|
|
|
|
the subprocess module instead.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Modules to keep
|
|
|
|
|
===============
|
|
|
|
|
|
|
|
|
|
Some modules were originally proposed for deprecation.
|
|
|
|
|
|
2019-05-21 11:44:03 -04:00
|
|
|
|
.. csv-table:: Table 2: Withdrawn deprecations
|
|
|
|
|
:header: "Module", "Deprecated in", "Replacement"
|
|
|
|
|
:widths: 1, 1, 2
|
|
|
|
|
|
|
|
|
|
colorsys,\-,"colormath, colour, colorspacious, Pillow"
|
|
|
|
|
fileinput,\-,argparse
|
|
|
|
|
getopt,\-,"argparse, optparse"
|
|
|
|
|
optparse,**3.2**,argparse
|
|
|
|
|
wave,\-,
|
|
|
|
|
|
|
|
|
|
colorsys
|
|
|
|
|
--------
|
|
|
|
|
|
|
|
|
|
The `colorsys <https://docs.python.org/3/library/colorsys.html>`_ module
|
|
|
|
|
defines color conversion functions between RGB, YIQ, HSL, and HSV coordinate
|
|
|
|
|
systems.
|
|
|
|
|
|
|
|
|
|
Walter Dörwald, Petr Viktorin, and others requested to keep ``colorsys``. The
|
|
|
|
|
module is useful to convert CSS colors between coordinate systems. The
|
|
|
|
|
implementation is simple, mature, and does not impose maintenance overhead
|
|
|
|
|
on core development.
|
|
|
|
|
|
2019-06-03 06:29:54 -04:00
|
|
|
|
The PyPI packages ``colormath``, ``colour``, and ``colorspacious`` provide more and
|
2019-05-21 11:44:03 -04:00
|
|
|
|
advanced features. The Pillow library is better suited to transform images
|
|
|
|
|
between color systems.
|
|
|
|
|
|
|
|
|
|
|
2019-05-21 07:05:45 -04:00
|
|
|
|
fileinput
|
|
|
|
|
---------
|
|
|
|
|
|
|
|
|
|
The `fileinput <https://docs.python.org/3/library/fileinput.html>`_ module
|
2019-06-03 06:29:54 -04:00
|
|
|
|
implements helpers to iterate over a list of files from ``sys.argv``. The
|
|
|
|
|
module predates the ``optparser`` and ``argparser`` modules. The same functionality
|
|
|
|
|
can be implemented with the ``argparser`` module.
|
2019-05-21 07:05:45 -04:00
|
|
|
|
|
|
|
|
|
Several core developers expressed their interest to keep the module in the
|
|
|
|
|
standard library, as it is handy for quick scripts.
|
|
|
|
|
|
|
|
|
|
|
2019-05-20 16:15:35 -04:00
|
|
|
|
getopt
|
|
|
|
|
------
|
|
|
|
|
|
|
|
|
|
The `getopt <https://docs.python.org/3/library/getopt.html>`_ module mimics
|
2019-06-03 06:29:54 -04:00
|
|
|
|
C's ``getopt()`` option parser.
|
2019-05-21 10:00:46 -04:00
|
|
|
|
|
2019-06-03 06:29:54 -04:00
|
|
|
|
Although users are encouraged to use ``argparse`` instead, the ``getopt`` module is
|
2019-05-21 10:00:46 -04:00
|
|
|
|
still widely used. The module is small, simple, and handy for C developers
|
|
|
|
|
to write simple Python scripts.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
optparse
|
|
|
|
|
--------
|
|
|
|
|
|
|
|
|
|
The `optparse <https://docs.python.org/3/library/optparse.html>`_ module is
|
2019-06-03 06:29:54 -04:00
|
|
|
|
the predecessor of the ``argparse`` module.
|
2019-05-21 10:00:46 -04:00
|
|
|
|
|
|
|
|
|
Although it has been deprecated for many years, it's still too widely used
|
|
|
|
|
to remove it.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
wave
|
2019-05-21 10:00:46 -04:00
|
|
|
|
----
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
The `wave <https://docs.python.org/3/library/wave.html>`_ module provides
|
2019-05-21 10:00:46 -04:00
|
|
|
|
support for the WAV sound format.
|
|
|
|
|
|
2022-02-07 14:30:56 -05:00
|
|
|
|
The module is not deprecated, because the WAV format is still relevant these
|
2019-05-21 10:00:46 -04:00
|
|
|
|
days. The ``wave`` module is also used in education, e.g. to show kids how
|
|
|
|
|
to make noise with a computer.
|
|
|
|
|
|
|
|
|
|
The module uses one simple function from the `audioop`_ module to perform
|
|
|
|
|
byte swapping between little and big endian formats. Before 24 bit WAV
|
|
|
|
|
support was added, byte swap used to be implemented with the ``array``
|
2019-06-03 06:29:54 -04:00
|
|
|
|
module. To remove ``wave``'s dependency on ``audioop``, the byte swap
|
2019-05-21 10:00:46 -04:00
|
|
|
|
function could be either be moved to another module (e.g. ``operator``) or
|
2019-06-03 06:29:54 -04:00
|
|
|
|
the ``array`` module could gain support for 24-bit (3-byte) arrays.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Discussions
|
|
|
|
|
===========
|
|
|
|
|
|
2019-06-03 06:29:54 -04:00
|
|
|
|
* Elana Hashman and Nick Coghlan suggested to keep the ``getopt`` module.
|
|
|
|
|
* Berker Peksag proposed to deprecate and removed ``msilib``.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
* Brett Cannon recommended to delay active deprecation warnings and removal
|
2019-06-03 06:29:54 -04:00
|
|
|
|
of modules like ``imp`` until Python 3.10. Version 3.8 will be released
|
|
|
|
|
shortly before Python 2 reaches end-of-life. A delay reduced churn for
|
2019-05-20 16:15:35 -04:00
|
|
|
|
users that migrate from Python 2 to 3.8.
|
|
|
|
|
* At one point, distutils was mentioned in the same sentence as this PEP.
|
|
|
|
|
To avoid lengthy discussion and delay of the PEP, I decided against dealing
|
|
|
|
|
with distutils. Deprecation of the distutils package will be handled by
|
|
|
|
|
another PEP.
|
|
|
|
|
* Multiple people (Gregory P. Smith, David Beazley, Nick Coghlan, ...)
|
|
|
|
|
convinced me to keep the `wave`_ module. [4]_
|
|
|
|
|
* Gregory P. Smith proposed to deprecate `nntplib`_. [4]_
|
2019-05-21 07:05:45 -04:00
|
|
|
|
* Andrew Svetlov mentioned the ``socketserver`` module is questionable.
|
|
|
|
|
However it's used to implement ``http.server`` and ``xmlrpc.server``. The
|
|
|
|
|
stdlib doesn't have a replacement for the servers, yet.
|
|
|
|
|
|
|
|
|
|
|
2022-01-25 17:51:26 -05:00
|
|
|
|
Rejected Ideas
|
|
|
|
|
==============
|
|
|
|
|
|
|
|
|
|
Creating/maintaining a separate repo for the deprecated modules
|
|
|
|
|
---------------------------------------------------------------
|
|
|
|
|
|
|
|
|
|
It was previously proposed to create a separate repository containing the
|
|
|
|
|
deprecated modules packaged for installation. One of the PEP authors went so far
|
|
|
|
|
as to create a `demo repository <https://github.com/tiran/legacylib>`_ . In the
|
|
|
|
|
end, though, it was decided that the added workload to create and maintain such
|
|
|
|
|
a repo officially wasn't justified, as the source code will continue to be
|
|
|
|
|
available in the CPython repository for people to vendor as necessary. Similar
|
|
|
|
|
work has also not been done when previous modules were deprecated and removed,
|
|
|
|
|
and it seemingly wasn't an undue burden on the community.
|
|
|
|
|
|
|
|
|
|
|
2019-05-21 07:05:45 -04:00
|
|
|
|
Update history
|
|
|
|
|
==============
|
|
|
|
|
|
|
|
|
|
Update 1
|
|
|
|
|
--------
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
2022-01-25 17:51:26 -05:00
|
|
|
|
* Deprecate parser module
|
2019-05-21 07:05:45 -04:00
|
|
|
|
* Keep `fileinput`_ module
|
2019-05-28 01:51:25 -04:00
|
|
|
|
* Elaborate why ``crypt`` and ``spwd`` are dangerous and bad
|
2019-05-21 07:05:45 -04:00
|
|
|
|
* Improve sections for `cgitb`_, `colorsys`_, `nntplib`_, and `smtpd`_ modules
|
2019-05-28 01:51:25 -04:00
|
|
|
|
* The `colorsys`_, ``crypt``, `imghdr`_, `sndhdr`_, and ``spwd`` sections now
|
2019-06-03 06:29:54 -04:00
|
|
|
|
list suitable substitutions
|
2019-05-21 07:05:45 -04:00
|
|
|
|
* Mention that ``socketserver`` is going to stay for ``http.server`` and
|
|
|
|
|
``xmlrpc.server``
|
2019-05-21 10:00:46 -04:00
|
|
|
|
* The future maintenance section now states that the deprecated modules
|
2019-06-03 06:29:54 -04:00
|
|
|
|
may be adopted by Python community members
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
2019-05-21 11:44:03 -04:00
|
|
|
|
Update 2
|
|
|
|
|
--------
|
|
|
|
|
|
|
|
|
|
* Keep ``colorsys`` module
|
2019-05-22 06:57:25 -04:00
|
|
|
|
* Add experts
|
2019-05-22 07:32:12 -04:00
|
|
|
|
* Redirect discussions to discuss.python.org
|
2019-05-28 01:51:25 -04:00
|
|
|
|
* Deprecate `telnetlib`_
|
|
|
|
|
* Deprecate compat32 policy of email package
|
|
|
|
|
* Add creation year to overview table
|
|
|
|
|
* Mention :pep:`206` and :pep:`3108`
|
|
|
|
|
* Update sections for ``aifc``, ``audioop``, ``cgi``, and ``wave``.
|
2019-05-21 11:44:03 -04:00
|
|
|
|
|
2020-10-22 14:18:54 -04:00
|
|
|
|
Update 3
|
|
|
|
|
--------
|
|
|
|
|
* Keep the legacy email API modules. Internal deprecations will be
|
|
|
|
|
handled separately.
|
|
|
|
|
|
2022-01-25 17:51:26 -05:00
|
|
|
|
Update 4
|
|
|
|
|
--------
|
|
|
|
|
* Add Brett as a co-author.
|
|
|
|
|
* Retarget the PEP for Python 3.11.
|
2022-02-04 18:46:03 -05:00
|
|
|
|
* Examples of how to replace the relevant parts of ``cgi``
|
|
|
|
|
(thanks Martijn Pieters).
|
2022-01-25 17:51:26 -05:00
|
|
|
|
|
2019-05-21 11:44:03 -04:00
|
|
|
|
|
2019-05-20 16:15:35 -04:00
|
|
|
|
References
|
|
|
|
|
==========
|
|
|
|
|
|
|
|
|
|
.. [1] https://en.wikipedia.org/wiki/Open_Sound_System#Free,_proprietary,_free
|
|
|
|
|
.. [2] https://man.openbsd.org/ossaudio
|
|
|
|
|
.. [3] https://blogs.msmvps.com/installsite/blog/2015/05/03/the-future-of-windows-installer-msi-in-the-light-of-windows-10-and-the-universal-windows-platform/
|
|
|
|
|
.. [4] https://twitter.com/ChristianHeimes/status/1130257799475335169
|
|
|
|
|
.. [5] https://twitter.com/dabeaz/status/1130278844479545351
|
2022-02-07 19:50:53 -05:00
|
|
|
|
.. [6] https://mail.python.org/pipermail/python-dev/2019-May/157634.html
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Copyright
|
|
|
|
|
=========
|
|
|
|
|
|
2022-01-25 17:51:26 -05:00
|
|
|
|
This document is placed in the public domain or under the
|
|
|
|
|
CC0-1.0-Universal license, whichever is more permissive.
|
2019-05-20 16:15:35 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
..
|
|
|
|
|
Local Variables:
|
|
|
|
|
mode: indented-text
|
|
|
|
|
indent-tabs-mode: nil
|
|
|
|
|
sentence-end-double-space: t
|
|
|
|
|
fill-column: 70
|
|
|
|
|
coding: utf-8
|
|
|
|
|
End:
|