131 lines
4.7 KiB
Plaintext
131 lines
4.7 KiB
Plaintext
PEP: 291
|
||
Title: Backward Compatibility for Standard Library
|
||
Version: $Revision$
|
||
Last-Modified: $Date$
|
||
Author: nnorwitz@gmail.com (Neal Norwitz)
|
||
Status: Active
|
||
Type: Informational
|
||
Created: 06-Jun-2002
|
||
Post-History:
|
||
Python-Version: 2.3
|
||
|
||
|
||
Abstract
|
||
|
||
This PEP describes the packages and modules in the standard
|
||
library which should remain backward compatible with previous
|
||
versions of Python. If a package is not listed here, then it need
|
||
only remain compatible with the version of Python it is
|
||
distributed with.
|
||
|
||
|
||
Rationale
|
||
|
||
Authors have various reasons why packages and modules should
|
||
continue to work with previous versions of Python. In order to
|
||
maintain backward compatibility for these modules while moving the
|
||
rest of the standard library forward, it is necessary to know
|
||
which modules can be modified and which should use old and
|
||
possibly deprecated features.
|
||
|
||
Generally, authors should attempt to keep changes backward
|
||
compatible with the previous released version of Python in order
|
||
to make bug fixes easier to backport.
|
||
|
||
In addition to a package or module being listed in this PEP,
|
||
authors must add a comment at the top of each file documenting
|
||
the compatibility requirement.
|
||
|
||
When a major version of Python is released, a Subversion branch is
|
||
created for continued maintenance and bug fix releases. A package
|
||
version on a branch may have a different compatibility requirement
|
||
than the same package on the trunk (i.e. current bleeding-edge
|
||
development). Where appropriate, these branch compatibilities are
|
||
listed below.
|
||
|
||
|
||
Features to Avoid
|
||
|
||
The following list contains common features to avoid in order
|
||
to maintain backward compatibility with each version of Python.
|
||
This list is not complete! It is only meant as a general guide.
|
||
|
||
Note that the features below were implemented in the version
|
||
following the one listed. For example, features listed next to
|
||
1.5.2 were implemented in 2.0.
|
||
|
||
Version Features to Avoid
|
||
------- -----------------
|
||
1.5.2 string methods, Unicode, list comprehensions,
|
||
augmented assignment (eg, +=), zip(), import x as y,
|
||
dict.setdefault(), print >> f,
|
||
calling f(*args, **kw), plus all features below
|
||
|
||
2.0 nested scopes, rich comparisons,
|
||
function attributes, plus all features below
|
||
|
||
2.1 use of object or new-style classes, iterators,
|
||
using generators, nested scopes, or //
|
||
without from __future__ import ... statement,
|
||
plus all features below
|
||
|
||
2.2 bool, True, False, basestring, enumerate(),
|
||
{}.pop(), PendingDeprecationWarning,
|
||
Universal Newlines, plus all features below
|
||
|
||
2.3 generator expressions, multi-line imports,
|
||
decorators, int/long unification, set/frozenset,
|
||
reversed(), sorted(), "".rsplit()
|
||
|
||
|
||
Backward Compatible Packages, Modules, and Tools
|
||
|
||
Package/Module Maintainer(s) Python Version Notes
|
||
-------------- ------------- -------------- -----
|
||
bsddb Greg Smith 2.1
|
||
Barry Warsaw
|
||
compiler Jeremy Hylton 2.1
|
||
decimal Raymond Hettinger 2.3 [2]
|
||
email Barry Warsaw 2.1 / 2.3 [1]
|
||
logging Vinay Sajip 1.5.2
|
||
sre Fredrik Lundh 2.1
|
||
subprocess Peter Astrand 2.2
|
||
xml (PyXML) Martin v. Loewis 2.0
|
||
xmlrpclib Fredrik Lundh 2.1
|
||
modulefinder Thomas Heller 2.2
|
||
Just van Rossum
|
||
platform Marc-Andre Lemburg 1.5.2
|
||
ctypes Thomas Heller 2.3
|
||
|
||
Tool Maintainer(s) Python Version
|
||
---- ------------- --------------
|
||
None
|
||
|
||
|
||
Notes
|
||
-----
|
||
|
||
[1] The email package version 2 was distributed with Python up to
|
||
Python 2.3, and this must remain Python 2.1 compatible. email
|
||
package version 3 will be distributed with Python 2.4 and will
|
||
need to remain compatible only with Python 2.3.
|
||
|
||
[2] Specification updates will be treated as bugfixes and backported.
|
||
Python 2.3 compatibility will be kept for at least Python 2.4.
|
||
The decision will be revisited for Python 2.5 and not changed
|
||
unless compelling advantages arise.
|
||
|
||
|
||
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
|
||
End:
|