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

goodger at users.sourceforge.net goodger at users.sourceforge.net
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. !

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