Introduction
When new modules were added to the standard Python library in the
past, it was not possible to foresee whether they would still be
useful in the future. Even though Python "Comes With Batteries
Included", batteries may discharge over time. Carrying old
modules around is a burden on the maintainer, especially when
there is no interest in the module anymore.
At the same time, removing a module from the distribution is
difficult, as it is not known in general whether anybody is still
using it. This PEP defines a procedure for removing modules from
the standard Python library. Usage of a module may be
`deprecated', which means that it may be removed from a future
Python release. The rationale for deprecating a module is also
collected in this PEP. If the rationale turns out faulty, the
module may become `undeprecated'.
Procedure for declaring a module deprecated
Since the status of module deprecation is recorded in this PEP,
proposals for deprecating modules MUST be made by providing a
change to the text of this PEP, which SHOULD be a patch posted to
SourceForge, or sent by mail to the author of this PEP.
A proposal for deprecation of the module MUST include the date of
the proposed deprecation and a rationale for deprecating it. In
addition, the proposal MUST include a change to the documentation
of the module; deprecation is indicated by saying that the module
is "obsolete" or "deprecated". The proposal MAY include a patch
for the module's source code to indicate deprecation there as
well.
It is expected that deprecated modules are included in the Python
releases that immediately follows the deprecation; later releases
may ship without the deprecated modules.
Procedure for declaring a module undeprecated
When a module becomes deprecated, a rationale is given for its
deprecation. In some cases, an alternative interface for the same
functionality is provided, so the old interface is deprecated. In
other cases, the need for having the functionality of the module
may not exist anymore.
If the rationale is faulty, again a change to this PEP's text MUST
be submitted. This change MUST include the date of undeprecation
and a rationale for undeprecation. Modules that are undeprecated
under this procedure MUST be listed in this PEP for at least one
major release of Python.
Obsolete modules
A number of modules are already listed as obsolete in the library
documentation. These are listed here for completeness.
addpack, cmp, cmpcache, codehack, dircmp, dump, fmt, lockfile,
newdir, Para, poly, regex, regsub, tb, timing, util, whatsound,
tzmod, find, grep, packmail, ni, rand, soundex, cl, sv
All these modules have been declared as obsolete in Python 2.0,
some even earlier.
Deprecated modules
Module name: posixfile
Rationale: Locking is better done by fcntl.lockf().
Date: Before 1-Oct-2000.
Documentation: Already documented as obsolete.
Module name: gopherlib
Rationale: The gopher protocol is not in active use anymore.
Date: 1-Oct-2000.
Documentation: TBD
Module name: rgbimgmodule
Rationale: In a 2001-04-24 c.l.py post, Jason Petrone mentions
that he occasionally uses it; no other references to
its use can be found as of 2003-11-19.
Date: 1-Oct-2000
Documentation: TBD
Module name: pre
Rationale: The underlying PCRE engine doesn't support Unicode, and
has been unmaintained since Python 1.5.2.
Date: 10-Apr-2002
Documentation: It was only mentioned as an implementation detail,
and never had a section of its own. This mention
has now been removed.
Module name: whrandom
Rationale: The module's default seed computation was
inherently insecure; the random module should be
used instead.
Date: 11-Apr-2002
Documentation: This module has been documented as obsolete since
Python 2.1, but listing in this PEP was neglected.
The deprecation warning will be added to the module
one year after Python 2.3 is released, and the
module will be removed one year after that.
Module name: rfc822
Rationale: Supplanted by Python 2.2's email package.
Date: 18-Mar-2002
Documentation: TBD
Module name: mimetools
Rationale: Supplanted by Python 2.2's email package.
Date: 18-Mar-2002
Documentation: TBD
Module name: MimeWriter
Rationale: Supplanted by Python 2.2's email package.
Date: 18-Mar-2002
Documentation: TBD
Module name: mimify
Rationale: Supplanted by Python 2.2's email package.
Date: 18-Mar-2002
Documentation: TBD
Module name: rotor
Rationale: Uses insecure algorithm.
Date: 24-Apr-2003
Documentation: TBD
Module name: TERMIOS.py
Rationale: The constants in this file are now in the 'termios' module.
Date: 10-Aug-2004
Documentation: This module has been documented as obsolete since
Python 2.1, but listing in this PEP was neglected.
Module name: statcache
Rationale: Using the cache can be fragile and error-prone;
applications should just use os.stat() directly.
Date: 10-Aug-2004
Documentation: This module has been documented as obsolete since
Python 2.2, but listing in this PEP was neglected.
Module name: mpz
Rationale: Third-party packages provide similiar features
and wrap more of GMP's API.
Date: 10-Aug-2004
Documentation: This module has been documented as obsolete since
Python 2.2, but listing in this PEP was neglected.
Module name: xreadlines
Rationale: Using 'for line in file', introduced in 2.3, is preferable.
Date: 10-Aug-2004
Documentation: This module has been documented as obsolete since
Python 2.3, but listing in this PEP was neglected.
Undeprecated modules
None.