635 lines
18 KiB
Plaintext
635 lines
18 KiB
Plaintext
PEP: 3108
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Title: Standard Library Reorganization
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Version: $Revision$
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Last-Modified: $Date$
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Author: Brett Cannon <brett@python.org>
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Status: Draft
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Type: Standards Track
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Python-Version: 3.0
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Content-Type: text/x-rst
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Created: 01-Jan-2007
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Post-History:
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Abstract
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========
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Just like the language itself, Python's standard library (stdlib) has
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grown over the years to be very rich. But over time some modules
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have lost their need to be included with Python. There has also been
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an introduction of a naming convention for modules since Python's
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inception that not all modules follow.
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Python 3.0 has presented a chance to remove modules that do not have
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long term usefulness. This chance also allows for the renaming of
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modules so that they follow the Python style guide [#pep-0008]_. This
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PEP lists modules that should not be included in Python 3.0 and what
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modules need to be renamed.
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Modules to Remove
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=================
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Guido pronounced that "silly old stuff" is to be deleted from the
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stdlib for Py3K [#silly-old-stuff]_. This is open-ended on purpose.
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Each module to be removed needs to have a justification as to why it
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should no longer be distributed with Python. This can range from the
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module being deprecated in Python 2.x to being for a platform that is
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no longer widely used.
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This section of the PEP lists the various modules to be removed. Each
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subsection represents a different reason for modules to be
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removed. Each module must have a specific justification on top of
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being listed in a specific subsection so as to make sure only modules
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that truly deserve to be removed are in fact removed.
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When a reason mentions how long it has been since a module has been
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"uniquely edited", it is in reference to how long it has been since a
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checkin was done specifically for the module and not for a change that
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applied universally across the entire stdlib. If an edit time is not
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denoted as "unique" then it is the last time the file was edited,
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period.
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Previously deprecated
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---------------------
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PEP 4 lists all modules that have been deprecated in the stdlib
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[#pep-0004]_. All modules listed in the PEP at the time of the first
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alpha release of Python 3.0 will be removed.
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The entire contents of libold will also be removed. These modules
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have already been removed from being imported but are kept in the
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distribution for Python for users that rely upon the code.
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On top of the modules listed in PEP 4, other modules have been
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documented as deprecated but have yet to be added to PEP 4.
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============== ==========
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Module Deprecated
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============== ==========
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buildtools 2.3
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cfmfile 2.4
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macfs 2.3
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md5 2.5 [done]
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sha 2.5 [done]
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strop unknown
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xmllib unknown
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============== ==========
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Platform-specific with minimal use
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----------------------------------
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Python supports many platforms, some of which are not widely held.
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And on some of these platforms there are modules that have limited use
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to people on those platforms. Because of their limited usefulness it
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would be better to no longer burden the Python development team with
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their maintenance.
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* IRIX (which is no longer produced [#irix-retirement]_)
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+ AL/al [done]
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- Provides sound support on Indy and Indigo workstations.
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- Both workstations are no longer available.
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- Code has not been uniquely edited in three years.
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+ cd [done]
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- CD drive control for SGI systems.
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- SGI no longer sells machines with IRIX on them.
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- Code has not been uniquely edited in 14 years.
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+ DEVICE/GL/gl/cgen/cgensuport [done]
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- OpenGL access.
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- Has not been edited in at least eight years.
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- Third-party libraries provide better support (PyOpenGL [#pyopengl]_).
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+ FL/fl/flp [done]
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- Wrapper for the FORMS library [#irix-forms]_
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- FORMS has not been edited in 12 years.
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- Library is not widely used.
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- First eight hits on Google are for Python docs for fl.
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+ fm [done]
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- Wrapper to the IRIS Font Manager library.
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- Only available on SGI machines which no longer come with IRIX.
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+ imgfile [done]
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- Wrapper for SGI libimage library for imglib image files
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(``.rgb`` files).
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- Python Imaging Library provdes read-only support [#pil]_.
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- Not uniquely edited in 13 years.
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+ jpeg [done]
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- Wrapper for JPEG (de)compressor.
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- Code not uniquely edited in nine years.
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- Third-party libraries provide better support
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(Python Imaging Library [#pil]_).
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* Solaris
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+ SUNAUDIODEV/sunaudiodev
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- Access to the sound card on Sun machines.
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- Code not uniquely edited in over eight years.
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* Mac
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+ aetools/aepack/aetypes/MiniAEFrame
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- OSA support is better through third-party modules.
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* Appscript [#appscript]_.
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- Hard-coded endianness which breaks on Intel Macs.
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- Might need to rename if Carbon package dependent.
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+ applesingle
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- Undocumented.
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- AppleSingle is a binary file format for A/UX.
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- A/UX no longer distributed.
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+ autoGIL
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- Very bad model for using Python with the CFRunLoop.
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- Rename to _autogil if needed by Carbon package.
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+ Carbon.CF
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- Half-heared attempt.
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+ findertools
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- No longer useful.
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+ FrameWork
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- Poorly documented.
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- Not updated to support Carbon Events.
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+ icopen
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- Not needed on OS X.
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- Meant to replace 'open' which is usually a bad thing to do.
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+ videoreader
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- No longer used.
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+ W
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- No longer distributed with Python.
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Hardly used
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------------
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Some modules that are platform-independent are hardly used. This
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can be from how easy it is to implement the functionality from scratch
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or because the audience for the code is very small.
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* audiodev
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+ Undocumented.
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+ Not edited in five years.
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+ If removed sunaudio should go as well (also undocumented; not
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edited in over seven years).
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* imputil
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+ Undocumented.
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+ Never updated to support absolute imports.
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* mutex
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+ Easy to implement using a semaphore and a queue.
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+ Cannot block on a lock attempt.
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+ Not uniquely edited since its addition 15 years ago.
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* repr
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+ Controls output of the repr of objects.
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+ String slicing and string interpolation can do similar work.
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+ Used by pdb, but do not need to expose API.
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* stringold [done]
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+ Function versions of the methods on string objects.
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+ Obsolete since Python 1.6.
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+ Any functionality not in the string object or module will be moved
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to the string module (mostly constants).
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* symtable/_symtable
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+ Undocumented.
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* toaiff
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+ Undocumented.
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+ Requires ``sox`` library to be installed on the system.
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* user
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+ Easily handled by allowing the application specify its own
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module name, check for existence, and import if found.
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* new
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+ Just a rebinding of names from the 'types' module.
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+ Can also call ``type`` built-in to get most types easily.
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+ Docstring states the module is no longer useful as of revision
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27241 (2002-06-15).
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* pure
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+ Written before Pure Atria was bought by Rational which was then
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bought by IBM (in other words, very old).
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Obsolete
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--------
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Becoming obsolete signifies that either another module in the stdlib
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or a widely distributed third-party library provides a better solution
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for what the module is meant for.
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* Bastion/rexec [done]
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+ Restricted execution / security.
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+ Turned off in Python 2.3.
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+ Modules deemed unsafe.
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* bsddb185 [done]
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+ Superceded by bsddb3
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+ Not built by default.
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+ Documentation specifies that the "module should never be used
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directly in new code".
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* commands [only getstatus(), does whole module go?]/popen2 [done]
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+ subprocess module replaces them [#pep-0324]_.
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* dl
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+ ctypes provides better support for same functionality.
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* fpformat
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+ All functionality is supported by string interpolation.
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* getopt
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+ optparse provides better functionality.
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+ But ...
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- getopt is still widely used.
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- optparse does not handle the issue of when people set
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incompatible options very well.
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- optparse does not allow option arguments to be optional.
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* ihooks
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+ Undocumented.
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+ For use with rexec which has been turned off since Python 2.3.
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* imageop
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+ Better support by third-party libraries
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(Python Imaging Library [#pil]_).
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* linuxaudiodev
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+ Replaced by ossaudiodev.
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* stat
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+ ``os.stat`` now returns a tuple with attributes.
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+ Functions in the module should be made into methods for the object
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returned by os.stat.
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* statvfs
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+ ``os.statvfs`` now returns a tuple with attributes.
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* thread
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+ People should use 'threading' instead.
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- Rename 'thread' to _thread.
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- Deprecate dummy_thread and rename _dummy_thread.
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- Move thread.get_ident over to threading.
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+ Guido has previously supported the deprecation
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[#thread-deprecation]_.
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Modules to Rename
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=================
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Along with the stdlib gaining some modules that are no longer
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relevant, there is also the issue of naming. Many modules existed in
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the stdlib before PEP 8 came into existence [#pep-0008]_. This has
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led to some naming inconsistencies that should be addressed.
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Any module that has been suggested for removal and does not meet the
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required naming scheme is *not* listed below.
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PEP 8 violations
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----------------
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PEP 8 specifies that modules "should have short, all-lowercase names"
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where "underscores can be used ... if it improves readability"
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[#pep-0008]_. The use of underscores is discouraged in package names.
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================== ==================================================
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Current Name Replacement Name
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================== ==================================================
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_winreg winreg (rename also because module has a public
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interface and thus should not have a leading
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underscore)
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BaseHTTPServer base_http_server
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Carbon carbon
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CGIHTTPServer cgi_http_server
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ColorPicker colorpicker
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ConfigParser configparser
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Cookie cookie
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copy_reg copyreg
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DocXMLRPCServer doc_xmlrpc_server
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EasyDialogs easydialogs
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HTMLParser htmlparser
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MacOS macos
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Nav nav
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PixMapWrapper pixmap_wrapper
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Queue queue
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repr reprlib (rename because module name shadows a
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built-in)
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ScrolledText scrolledtext
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SimpleHTTPServer simple_http_server
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SimpleXMLRPCServer simple_xmlrpc_server
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SocketServer socketserver
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StringIO stringio
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Tix tix
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Tkinter tkinter
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UserDict userdict
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UserList userlist
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UserString userstring
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================== ==================================================
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Merging C and Python implementations of the same interface
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----------------------------------------------------------
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Several interfaces have both a Python and C implementation. While it
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is great to have a C implementation for speed with a Python
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implementation as fallback, there is no need to expose the two
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implementations independently in the stdlib. For Python 3.0 all
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interfaces with two implementations will be merged into a single
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public interface.
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The C module is to be given a leading underscore to delineate the fact
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that it is not the reference implementation (the Python implementation
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is). This means that any semantic difference between the C and Python
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versions must be dealt with before Python 3.0 or else the C
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implementation will be removed until it can be fixed.
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One interface that is not listed below is xml.etree.ElementTree. This
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is an externally maintained module and thus is not under the direct
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control of the Python development team for renaming. See `Open
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Issues`_ for a discussion on this.
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* pickle/cPickle
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+ Rename cPickle to _pickle.
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+ Semantic completeness of C implementation *not* verified.
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* profile/cProfile
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+ Rename cProfile to _profile.
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+ Semantic completeness of C implementation *not* verified.
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* StringIO/cStringIO
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+ Rename StringIO to stringio.
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+ Rename cStringIO to _stringio.
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+ Semantic completeness of C implementation *not* verified.
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No public, documented interface
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-------------------------------
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There are several modules in the stdlib that have no defined public
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interface. These modules exist as support code for other modules that
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are exposed. Because they are not meant to be used directly they
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should be renamed to reflect this fact.
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============ ===============================
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Current Name Replacement Name
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============ ===============================
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bdb _bdb
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cl _cl
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markupbase _markupbase
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opcode _opcode
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dummy_thread _dummy_thread (assuming thread
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is deprecated)
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============ ===============================
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Poorly chosen names
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-------------------
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A few modules have names that were poorly chosen in hindsight. They
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should be renamed so as to prevent their bad name from perpetuating
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beyond the 2.x series.
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================= ===============================
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Current Name Replacement Name
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================= ===============================
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test.test_support test.support
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================= ===============================
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Transition Plan
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===============
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For modules to be removed
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-------------------------
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For the removal of modules that are continuing to exist in the Python
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2.x series (i.e., not deprecated explicitly in the 2.x series), a
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proper warning will be set that is silenced by default;
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PendingDeprecationWarning initially, moving over to a Py3K-specific
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warning later if one comes into existence.
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Renaming of modules
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-------------------
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For modules that are renamed, stub modules will be created with the
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original names and be kept in a package within the stdlib. The need
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to keep them within a package is to prevent naming conflicts
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with case-insensitive filesystems.
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These stub modules will import the module code based on the new
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naming. The same type of warning being raised by modules being
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removed will be raised in the stub modules.
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Support in the 2to3 refactoring tool for renames will also be used
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[#2to3]_. Import statements will be rewritten so that only the import
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statement and none of the rest of the code needs to be touched. This
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will be accomplished by using the ``as`` keyword in import statments
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to bind in the module namespace to the old name while importing based
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on the new name.
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Open Issues
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===========
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Renaming of modules maintained outside of the stdlib
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----------------------------------------------------
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xml.etree.ElementTree not only does not meet PEP 8 naming standards
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but it also has an exposed C implementation [#pep-0008]_. It is an
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externally maintained package, though [#pep-0360]_. A request will be
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made for the maintainer to change the name so that it matches PEP 8
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and hides the C implementation.
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Rejected Ideas
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==============
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Modules that were originally suggested for removal
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--------------------------------------------------
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* asynchat/asyncore
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+ Josiah Carlson has said he will maintain the modules.
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* base64/quopri/uu
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+ All still widely used.
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+ 'codecs' module does not provide as nice of an API for basic
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usage.
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* fileinput
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+ Useful when having to work with stdin.
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* nis
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+ Testimonials from people that new installations of NIS are still
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occurring
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* telnetlib
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+ Really handy for quick-and-dirty remote access.
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+ Some hardware supports using telnet for configuration and
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querying.
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Introducing a new top-level package
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-----------------------------------
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It has been suggested that the entire stdlib be placed within its own
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package. This PEP will not address this issue as it has its own
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design issues (naming, does it deserve special consideration in import
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semantics, etc.). Everything within this PEP can easily be handled if
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a new top-level package is introduced.
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Introducing new packages to contain theme-related modules
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---------------------------------------------------------
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During the writing of this PEP it was noticed that certain themes
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appeared in the stdlib. In the past people have suggested introducing
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new packages to help collect modules that share a similar theme (e.g.,
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audio). An Open Issue was created to suggest some new packages to
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introduce.
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In the end, though, not enough support could be pulled together to
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warrant moving forward with the idea. In the future either a separate
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PEP trying to do a large reorganization of the stdlib or doing it
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piece-meal, one package at a time, will be required.
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References
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==========
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.. [#pep-0004] PEP 4: Deprecation of Standard Modules
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(http://www.python.org/dev/peps/pep-0004/)
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.. [#pep-0008] PEP 8: Style Guide for Python Code
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(http://www.python.org/dev/peps/pep-0008/)
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.. [#pep-0324] PEP 324: subprocess -- New process module
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(http://www.python.org/dev/peps/pep-0324/)
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.. [#pep-0360] PEP 360: Externally Maintained Packages
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(http://www.python.org/dev/peps/pep-0360/)
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.. [#module-index] Python Documentation: Global Module Index
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(http://docs.python.org/modindex.html)
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.. [#timing-module] Python Library Reference: Obsolete
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(http://docs.python.org/lib/obsolete-modules.html)
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.. [#silly-old-stuff] Python-Dev email: "Py3k release schedule worries"
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||
(http://mail.python.org/pipermail/python-3000/2006-December/005130.html)
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||
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.. [#thread-deprecation] Python-Dev email: Autoloading?
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||
(http://mail.python.org/pipermail/python-dev/2005-October/057244.html)
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.. [#py-dev-summary-2004-11-01] Python-Dev Summary: 2004-11-01
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(http://www.python.org/dev/summary/2004-11-01_2004-11-15/#id10)
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|
||
.. [#2to3] 2to3 refactoring tool
|
||
(http://svn.python.org/view/sandbox/trunk/2to3/)
|
||
|
||
.. [#pyopengl] PyOpenGL
|
||
(http://pyopengl.sourceforge.net/)
|
||
|
||
.. [#pil] Python Imaging Library (PIL)
|
||
(http://www.pythonware.com/products/pil/)
|
||
|
||
.. [#twisted] Twisted
|
||
(http://twistedmatrix.com/trac/)
|
||
|
||
.. [#irix-retirement] SGI Press Release:
|
||
End of General Availability for MIPS IRIX Products -- December 2006
|
||
(http://www.sgi.com/support/mips_irix.html)
|
||
|
||
.. [#irix-forms] FORMS Library by Mark Overmars
|
||
(ftp://ftp.cs.ruu.nl/pub/SGI/FORMS)
|
||
|
||
.. [#sun-au] Wikipedia: Au file format
|
||
(http://en.wikipedia.org/wiki/Au_file_format)
|
||
|
||
.. [#appscript] appscript
|
||
(http://appscript.sourceforge.net/)
|
||
|
||
|
||
Copyright
|
||
=========
|
||
|
||
This document has been placed in the public domain.
|
||
|
||
|
||
|
||
..
|
||
Local Variables:
|
||
mode: indented-text
|
||
indent-tabs-mode: nil
|
||
sentence-end-double-space: t
|
||
fill-column: 70
|
||
coding: utf-8
|
||
End:
|