[Python-checkins] python/nondist/peps pep-0328.txt,1.5,1.6

Sun May 2 12:32:35 EDT 2004

Update of /cvsroot/python/python/nondist/peps
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv13223
Modified Files:
	pep-0328.txt 
Log Message:
upadte from Aahz
Index: pep-0328.txt
===================================================================
RCS file: /cvsroot/python/python/nondist/peps/pep-0328.txt,v
retrieving revision 1.5
retrieving revision 1.6
diff -C2 -d -r1.5 -r1.6
*** pep-0328.txt	6 Apr 2004 13:09:14 -0000	1.5
--- pep-0328.txt	2 May 2004 16:32:32 -0000	1.6
***************
*** 42,49 ****

 You may use relative imports freely. In Python 2.5, any ``import``
! statement that results in an intra-package import will generate a
! ``PendingDeprecation`` warning (this also applies to ``from <> import``
! that fails to use the relative import syntax). In Python 2.6, ``import``
! will always be an absolute import.

--- 42,50 ----

 You may use relative imports freely. In Python 2.5, any ``import``
! statement that results in an intra-package import will raise
! ``DeprecationWarning`` (this also applies to ``from <> import`` that
! fails to use the relative import syntax). In Python 2.6, ``import`` will
! always be an absolute import (and the ``__future__`` directive will no
! longer be needed).

***************
*** 72,76 ****
 LEFT, DISABLED, NORMAL, RIDGE, END)

! This part of the proposal already has BDFL approval.

--- 73,77 ----
 LEFT, DISABLED, NORMAL, RIDGE, END)

! This part of the proposal had BDFL approval from the beginning.

***************
*** 78,82 ****
 ==============================

! In current Python, if you're reading a module located inside a
 package, it is not clear whether ::

--- 79,83 ----
 ==============================

! In Python 2.3 and earlier, if you're reading a module located inside a
 package, it is not clear whether ::

***************
*** 84,102 ****

 refers to a top-level module or to another module inside the package.
! Let's say today it refers to a module internal to the package. Then
! tomorrow, the standard library decides to add its own foo package that
! you'd like to use. You can't without renaming your internal module.
! To resolve these ambiguities, it is proposed that ``foo`` will always be a
! module or package reachable from ``sys.path``.

 Because this represents a change in semantics, absolute imports will
! be optional in Python 2.4 through the use of ::

 from __future__ import absolute_import

! This PEP will be updated when it is decided to make absolute imports
! the default, probably Python 2.5 or 2.6.
! 
! This part of the proposal already has BDFL approval.

--- 85,107 ----

 refers to a top-level module or to another module inside the package.
! As Python's library expands, more and more existing package internal
! modules suddenly shadow standard library modules by accident. It's a
! particularly difficult problem inside packages because there's no way to
! specify which module is meant. To resolve the ambiguity, it is proposed
! that ``foo`` will always be a module or package reachable from
! ``sys.path``. This is called an absolute import.
! 
! The python-dev community chose absolute imports as the default because
! they're the more common use case and because absolute imports can provide
! all the functionality of relative (intra-package) imports -- albeit at
! the cost of difficulty when renaming package pieces higher up in the
! hierarchy or when moving one package inside another.

 Because this represents a change in semantics, absolute imports will
! be optional in Python 2.4 and 2.5 through the use of ::

 from __future__ import absolute_import

! This part of the proposal had BDFL approval from the beginning.

***************
*** 208,227 ****

 Guido's Decision
! ----------------

! Guido has Pronounced [1]_ that relative imports will use leading dots,
! one per level of parent. Further discussion led to the following
! clarification of the semantics. Given a package layout::

! package
! subpackage1
! moduleX
! moduleY
! subpackage2
! moduleZ
! moduleA

! Assuming that the current file is ``moduleX.py``, following are correct
! usages of the new syntax::

 from .moduleY import spam
--- 213,238 ----

 Guido's Decision
! ================

! Guido has Pronounced [1]_ that relative imports will use leading dots.
! A single leading dot indicates a relative import, starting with the
! current package. Two or more leading dots give a relative import to the
! parent(s) of the current package, one level per dot after the first.
! Here's a sample package layout::

! package/
! __init__.py
! subpackage1/
! __init__.py
! moduleX.py
! moduleY.py
! subpackage2/
! __init__.py
! moduleZ.py
! moduleA.py

! Assuming that the current file is either ``moduleX.py`` or
! ``subpackage1/__init__.py``, following are correct usages of the new
! syntax::

 from .moduleY import spam
***************
*** 237,243 ****
 ("insane" was the word Guido used).

! Reminder: relative imports must always use ``from <> import``;
! ``import <>`` is always absolute. Of course, absolute imports can use
! ``from <> import`` by omitting the leading dots.

--- 248,268 ----
 ("insane" was the word Guido used).

! Relative imports must always use ``from <> import``; ``import <>`` is
! always absolute. Of course, absolute imports can use ``from <> import``
! by omitting the leading dots. The reason ``import .foo`` is prohibited
! is because after ::
! 
! import XXX.YYY.ZZZ
! 
! then ::
! 
! XXX.YYY.ZZZ
! 
! is usable in an expression. But ::
! 
! .moduleY
! 
! is not usable in an expression.
! 