PEP: 3108 Title: Standard Library Reorganization Version: $Revision$ Last-Modified: $Date$ Author: Brett Cannon Status: Draft Type: Informational Python-Version: 3.0 Content-Type: text/x-rst Created: 01-Jan-2007 Post-History: Abstract ======== Just like the language itself, Python's standard library (stdlib) has grown over the years to be very rich. But over time some modules have lost their need to be included with Python. There has also been an introduction of a naming convention for modules since Python's inception that not all modules follow. Python 3.0 has presented a chance to remove modules that do not have long term usefulness. This chance also allows for the renaming of modules so that they follow the Python style guide [#pep-0008]_. This PEP lists modules that should not be included in Python 3.0 and what modules need to be renamed. Modules to Remove ================= Guido pronounced that "silly old stuff" is to be deleted from the stdlib for Py3K [#silly-old-stuff]_. This is open-ended on purpose. Each module to be removed needs to have a justification as to why it should no longer be distributed with Python. This can range from the module being deprecated in Python 2.x to being for a platform that is no longer widely used. This section of the PEP lists the various modules to be removed. Each subsection represents a different reason for modules to be removed. Each module must have a specific justification on top of being listed in a specific subsection so as to make sure only modules that truly deserve to be removed are in fact removed. When a reason mentions how long it has been since a module has been "uniquely edited", it is in reference to how long it has been since a checkin was done specifically for the module and not for a change that applied universally across the entire stdlib. If an edit time is not denoted as "unique" then it is the last time the file was edited, period. Previously deprecated --------------------- Modules in this section have been deprecated at some point in the Python 2.x release series but are currently still distributed with Python. Deprecation information is gathered either from PEP 4 or the Global Module Index [#pep-0004]_, [#module-index]_. Each module is listed with the Python version of initial deprecation. ============== ========== Module Deprecated ============== ========== buildtools 2.3 cfmfile 2.4 gopherlib 2.5 macfs 2.3 md5 2.5 mimetools 2.3 MimeWriter 2.3 mimefy 2.3 multifile 2.3 posixfile 1.5 rfc822 2.3 rgbimg 2.5 sha 2.5 ============== ========== Platform-specific with minimal use ---------------------------------- Python supports many platforms, some of which are not widely held. And on some of these platforms there are modules that have limited use to people on those platforms. Because of their limited usefulness it would be better to no longer burden the Python development team with their maintenance. * IRIX (which is no longer produced [#irix-retirement]_) + AL/al - Provides sound support on Indy and Indigo workstations. - Both workstations are no longer available. - Code has not been uniquely edited in three years. + cd - CD drive control for SGI systems. - SGI no longer sells machines with IRIX on them. - Code has not been uniquely edited in 14 years. + DEVICE/GL/gl/cgen/cgensuport - OpenGL access. - Has not been edited in at least eight years. - Third-party libraries provide better support (PyOpenGL [#pyopengl]_). + FL/fl/flp - Wrapper for the FORMS library [#irix-forms]_ - FORMS has not been edited in 12 years. - Library is not widely used. - First eight hits on Google are for Python docs for fl. + fm - Wrapper to the IRIS Font Manager library. - Only available on SGI machines which no longer come with IRIX. + imgfile - Wrapper for SGI libimage library for imglib image files (``.rgb`` files). - Python Imaging Library provdes read-only support [#pil]_. - Not uniquely edited in 13 years. + jpeg - Wrapper for JPEG (de)compressor. - Code not uniquely edited in nine years. - Third-party libraries provide better support (Python Imaging Library [#pil]_). + sv - Wrapper for Indigo video card. - Harware is no longer manufactured. - Undocumented. - Code not uniquely edited in 13 years. * Solaris + SUNAUDIODEV/sunaudiodev - Access to the sound card on Sun machines. - Code not uniquely edited in over eight years. * Mac + aetools/aepack/aetypes/MiniAEFrame - OSA support is better through third-party modules. * Appscript [#appscript]_. - Hard-coded endianness which breaks on Intel Macs. - Might need to rename if Carbon package dependent. + applesingle - Undocumented. - AppleSingle is a binary file format for A/UX. - A/UX no longer distributed. + autoGIL - Very bad model for using Python with the CFRunLoop. - Rename to _autogil if needed by Carbon package. + Carbon.CF - Half-heared attempt. + findertools - No longer useful. + FrameWork - Poorly documented. - Not updated to support Carbon Events. + icopen - Not needed on OS X. - Meant to replace 'open' which is usually a bad thing to do. + videoreader - No longer used. + W - No longer distributed with Python. Minimal usage ------------- Some modules that are platform-independent have minimal usage. This can be from how easy it is to implement the functionality from scratch or because the audience for the code is small. * audiodev + Undocumented. + Not edited in five years. + If removed sunaudio should go as well (also undocumented; not edited in over seven years). * imputil + Undocumented. + Never updated to support absolute imports. * mutex + Easy to implement using a semaphore and a queue. + Cannot block on a lock attempt. + Not uniquely edited since its addition 15 years ago. * repr + Controls output of the repr of objects. + String slicing and string interpolation can do similar work. + Used by pdb, but do not need to expose API. * symtable/_symtable + Undocumented. * toaiff + Undocumented. + Requires ``sox`` library to be installed on the system. * user + Easily handled by allowing the application specify its own module name, check for existence, and import if found. * new + Just a rebinding of names from the 'types' module. + Can also call ``type`` built-in to get most types easily. * pure + Written before Pure Atria was bought by Rational which was then bought by IBM (in other words, very old). Obsolete -------- Becoming obsolete signifies that either another module in the stdlib or a widely distributed third-party library provides a better solution for what the module is meant for. * Bastion/rexec + Restricted execution / security. + Turned off in Python 2.3. + Modules deemed unsafe. * commands/popen2 + subprocess module replaces them [#pep-0324]_. * dl + ctypes provides better support for same functionality. * fpformat + All functionality is supported by string interpolation. * getopt + optparse provides better functionality. + But ... - getopt is still widely used. - optparse does not handle the issue of when people set incompatible options very well. - optparse does not allow option arguments to be optional. * ihooks + Documented except for saying that module might be obsolete. + For use with rexec which has been turned off since Python 2.3. * imageop + Better support by third-party libraries (Python Imaging Library [#pil]_). * linuxaudiodev + Replaced by ossaudiodev. * stat + ``os.stat`` now returns a tuple with attributes. + Functions in the module should be made into methods for the object returned by os.stat. * statvfs + ``os.statvfs`` now returns a tuple with attributes. * strop + Implements functions used by 'string' module that have now become methods on the str type. * thread + People should use 'threading' instead. - Rename 'thread' to _thread. - Deprecate dummy_thread. * Rename to _mockthread. * Change of name better reflects modules purpose. + Guido has previously supported the deprecation [#thread-deprecation]_. * timing + Use timeit or time. + Documentation says the module is obsolete [#timing-module]_. Modules to Rename ================= Along with the stdlib gaining some modules that are no longer relevant, there is also the issue of naming. Many modules existed in the stdlib before PEP 8 came into existence [#pep-0008]_. This has led to some naming inconsistencies that should be addressed. Any module that has been suggested for removal and does not meet the required naming scheme is *not* listed below. PEP 8 violations ---------------- PEP 8 specifies that modules "should have short, lowercase names, without underscores" [#pep-0008]_. There is no mention, though, if this rule extends to modules contained within a package. The assumption is that underscores are acceptable in module names when they are contained within a package but that any uppercase letters is not. ================== ================================================== Current Name Replacement Name ================== ================================================== _winreg winreg (rename also because module has a public interface) BaseHTTPServer basehttpserver Carbon carbon CGIHTTPServer cgihttpserver ColorPicker colorpicker ConfigParser configparser Cookie cookie copy_reg copyreg DocXMLRPCServer docxmlrpcserver dummy_threading mockthreading (rename because "mock" makes more sense than "dummy" and rename already required) EasyDialogs easydialogs HTMLParser htmlparser MacOS macos Nav nav PixMapWrapper pixmapwrapper py_compile pycompile Queue queue repr reprlib (rename because module name shadows a built-in) ScrolledText scrolledtext SimpleHTTPServer simplehttpserver SimpleXMLRPCServer simplexmlrpcserver SocketServer socketserver StringIO stringio Tix tix Tkinter tkinter UserDict userdict UserList userlist UserString userstring ================== ================================================== Merging C and Python implementations of the same interface ---------------------------------------------------------- Several interfaces have both a Python and C implementation. While it is great to have a C implementation for speed with a Python implementation as fallback, there is no need to expose the two implementations independently in the stdlib. For Python 3.0 all interfaces with two implementations will be merged into a single public interface. The C module is to be given a leading underscore to delineate the fact that it is not the reference implementation (the Python implementation is). This means that any semantic difference between the C and Python versions must be dealt with before Python 3.0 or else the C implementation will be removed until it can be fixed. One interface that is not listed below is xml.etree.ElementTree. This is an externally maintained module and thus is not under the direct control of the Python development team for renaming. See `Open Issues`_ for a discussion on this. * pickle/cPickle + Rename cPickle to _pickle. + Semantic completeness of C implementation *not* verified. * profile/cProfile + Rename cProfile to _profile. + Semantic completeness of C implementation *not* verified. * StringIO/cStringIO + Rename StringIO to stringio. + Rename cStringIO to _stringio. + Semantic completeness of C implementation *not* verified. No public, documented interface ------------------------------- There are several modules in the stdlib that have no defined public interface. These modules exist as support code for other modules that are exposed. Because they are not meant to be used directly they should be renamed to reflect this fact. ============ =============================== Current Name Replacement Name ============ =============================== bdb _bdb cl _cl markupbase _markupbase opcode _opcode dummythread _mockthread (assuming the deprecation of 'thread' occurs) ============ =============================== Transition Plan =============== For modules to be removed ------------------------- A PendingDeprecationWarning will be set in Python 2.6 for all modules slated to be removed in Python 3.0. This will allow people to know which modules will not exist but without being overly noisy since PendingDeprecationWarning is by default silenced. For modules to be renamed ------------------------- Modules will be renamed in Python 2.6. The original names of the modules will still work but will raise a PendingDeprecationWarning upon import. The refactoring tool for transitioning to Python 3.0 will refactor imports that use the new names. Open Issues =========== Consolidate dependent modules together into a single module or package? ----------------------------------------------------------------------- The stdlib has several modules that have a level of dependency between them (e.g., urllib and urllib2). Usually one is a low-level module that provides basic abilities with a corresponding higher-level API is given in another module for simple use-cases. In Python 3.0 we could group these dependent modules together into a single module or package to better reflect their relationship. Keep in mind when looking at the groupings that deprecation or removal is also a possibility if there is enough overlap or a module is obsolete. * Cookie/cookielib * urllib/urllib2 (urlparse? httplib?) * cgi/cgitb * Tix/Tkinter * getpass/pwd/spwd/grp * mailbox/mhlib * anydbm/whichdbm * bsddb/dbhash * pickle/pickletools * HTMLParser/htmllib * ftplib/netrc * parser/symbol Consolidate certain modules with similar themes together in a package? ---------------------------------------------------------------------- Packages are often used to group together modules that have a similar theme but do not have any direct relationship or dependency upon each other. For Python 3.0 obvious groupings could be done since renaming of various modules is already occurring. Below is a list sectioned off into what types of obvious groupings there seem to be. No name for the suggested package (if not already existent) is being proposed. * collections + heapq + Queue + sets + UserDist + UserList + What to do with UserString? Have a package for Python implementations of built-in types instead of putting the User* modules into 'collections'? * mac + Various Mac-specific modules. + Same can be done for other platform-specific code. * Profiling + cProfile + profile + hotshot + pstats * email + imaplib + mailbox + mailcap + mhlib + poplib * Databases + anydbm + dbhash + dbm + bsddb + dumbdbm + gdbm + whichdb * Audio + aifc + audioop + chunk + ossaudiodev + sunau + wave + winsound * XML-RPC + DocXMLRPCServer + SimpleXMLRPCServer + xmlrpclib * Internet + BaseHTTPServer + cgi + CGIHTTPServer + cgitb + Cookie + cookielib + ftplib (?) + htmlentitydefs + htmllib + HTMLParser + httplib + netrc (?) + nntplib (?) + sgmllib (?) + SimpleHTTPServer + stringprep + urllib + urllib2 + urlparse + webbrowser + wsgiref * HTTP servers + BaseHTTPServer + CGIHTTPServer + DocXMLRPCServer + SimpleHTTPServer + SimpleXMLRPCServer + wsgiref Renaming of modules maintained outside of the stdlib ---------------------------------------------------- xml.etree.ElementTree not only does not meet PEP 8 naming standards but it also has an exposed C implementation [#pep-0008]_. It is an externally maintained package, though [#pep-0360]_. A request will be made for the maintainer to change the name so that it matches PEP 8 and hides the C implementation. Rejected Ideas ============== Modules that were suggested for removal but were saved ------------------------------------------------------ * asynchat/asyncore + Josiah Carlson has said he will help to maintain the modules. * base64/quopri/uu + All still widely used. + 'codecs' module does not provide as nice of an API for basic usage. * fileinput + Useful when having to work with stdin. * nis + Testimonials from people that new installations of NIS are still occurring out in the world. * telnetlib + Really handy for quick-and-dirty remote access. + Some hardware supports telnet for accessing it. Introducing a new top-level package ----------------------------------- It has been suggested that the entire stdlib be placed within its own package. This PEP will not address this issue as it has its own design issues (naming, does it deserve special consideration in import semantics, etc.). Everything within this PEP can easily be handled if a new top-level package is introduced. References ========== .. [#pep-0004] PEP 4: Deprecation of Standard Modules (http://www.python.org/dev/peps/pep-0004/) .. [#pep-0008] PEP 8: Style Guide for Python Code (http://www.python.org/dev/peps/pep-0008/) .. [#pep-0324] PEP 324: subprocess -- New process module (http://www.python.org/dev/peps/pep-0324/) .. [#pep-0360] PEP 360: Externally Maintained Packages (http://www.python.org/dev/peps/pep-0360/) .. [#module-index] Python Documentation: Global Module Index (http://docs.python.org/modindex.html) .. [#timing-module] Python Library Reference: Obsolete (http://docs.python.org/lib/obsolete-modules.html) .. [#silly-old-stuff] Python-Dev email: "Py3k release schedule worries" (http://mail.python.org/pipermail/python-3000/2006-December/005130.html) .. [#thread-deprecation] Python-Dev email: Autoloading? (http://mail.python.org/pipermail/python-dev/2005-October/057244.html) .. [#py-dev-summary-2004-11-01] Python-Dev Summary: 2004-11-01 (http://www.python.org/dev/summary/2004-11-01_2004-11-15/#id10) .. [#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: