[Python-checkins] cpython (2.7): Improve documentation for PEP 370 support in site module (#8617).
eric.araujo
python-checkins at python.org
Fri Aug 19 14:28:13 CEST 2011
http://hg.python.org/cpython/rev/b3f72b6450f1
changeset: 71957:b3f72b6450f1
branch: 2.7
user: Éric Araujo <merwok at netwok.org>
date: Fri Aug 19 08:20:01 2011 +0200
summary:
Improve documentation for PEP 370 support in site module (#8617).
site.USER_BASE and site.USER_SITE are now fully documented. PEP 370 is
outdated with respects to the Mac framework situation, but the code in
sysconfig and the example in the 3.2 What’s New document helped me find
the right values to document for Mac OS X.
The command-line interface of the site module is also described in the
module docs.
The purpose of the usercustomize module is explained in the site docs,
with a gentle introduction in the tutorial (right after the section that
talks about PYTHONSTARTUP; a comment mentions it should be moved from
the tutorial to another file, but that will be another bug).
Various markup and wording improvements were made along the way in the
site module docs. Duplicate and incomplete declarations of environment
variables have also been removed (the original bug report was actually
about these entries :). The site module docs are still a bit messy;
I’ll see about improving them for #11553.
All these sections are copiously interlinked and findable from the doc
indexes.
files:
Doc/library/site.rst | 128 +++++++++++++++-------
Doc/tutorial/interactive.rst | 7 +-
Doc/tutorial/interpreter.rst | 24 ++++-
Doc/using/cmdline.rst | 10 +-
4 files changed, 121 insertions(+), 48 deletions(-)
diff --git a/Doc/library/site.rst b/Doc/library/site.rst
--- a/Doc/library/site.rst
+++ b/Doc/library/site.rst
@@ -2,18 +2,21 @@
================================================
.. module:: site
- :synopsis: A standard way to reference site-specific modules.
+ :synopsis: Module responsible for site-specific configuration.
**Source code:** :source:`Lib/site.py`
--------------
+.. highlightlang:: none
+
**This module is automatically imported during initialization.** The automatic
import can be suppressed using the interpreter's :option:`-S` option.
.. index:: triple: module; search; path
-Importing this module will append site-specific paths to the module search path.
+Importing this module will append site-specific paths to the module search path
+and add a few builtins.
.. index::
pair: site-python; directory
@@ -28,11 +31,11 @@
if it refers to an existing directory, and if so, adds it to ``sys.path`` and
also inspects the newly added path for configuration files.
-A path configuration file is a file whose name has the form :file:`package.pth`
+A path configuration file is a file whose name has the form :file:`{name}.pth`
and exists in one of the four directories mentioned above; its contents are
additional items (one per line) to be added to ``sys.path``. Non-existing items
-are never added to ``sys.path``, but no check is made that the item refers to a
-directory (rather than a file). No item is added to ``sys.path`` more than
+are never added to ``sys.path``, and no check is made that the item refers to a
+directory rather than a file. No item is added to ``sys.path`` more than
once. Blank lines and lines beginning with ``#`` are skipped. Lines starting
with ``import`` (followed by space or tab) are executed.
@@ -45,8 +48,7 @@
For example, suppose ``sys.prefix`` and ``sys.exec_prefix`` are set to
:file:`/usr/local`. The Python X.Y library is then installed in
-:file:`/usr/local/lib/python{X.Y}` (where only the first three characters of
-``sys.version`` are used to form the installation path name). Suppose this has
+:file:`/usr/local/lib/python{X.Y}`. Suppose this has
a subdirectory :file:`/usr/local/lib/python{X.Y}/site-packages` with three
subsubdirectories, :file:`foo`, :file:`bar` and :file:`spam`, and two path
configuration files, :file:`foo.pth` and :file:`bar.pth`. Assume
@@ -79,86 +81,130 @@
After these path manipulations, an attempt is made to import a module named
:mod:`sitecustomize`, which can perform arbitrary site-specific customizations.
-If this import fails with an :exc:`ImportError` exception, it is silently
-ignored.
+It is typically created by a system administrator in the site-packages
+directory. If this import fails with an :exc:`ImportError` exception, it is
+silently ignored.
-.. index:: module: sitecustomize
+.. index:: module: usercustomize
+
+After this, an attempt is made to import a module named :mod:`usercustomize`,
+which can perform arbitrary user-specific customizations, if
+:data:`ENABLE_USER_SITE` is true. This file is intended to be created in the
+user site-packages directory (see below), which is part of ``sys.path`` unless
+disabled by :option:`-s`. An :exc:`ImportError` will be silently ignored.
Note that for some non-Unix systems, ``sys.prefix`` and ``sys.exec_prefix`` are
empty, and the path manipulations are skipped; however the import of
-:mod:`sitecustomize` is still attempted.
+:mod:`sitecustomize` and :mod:`usercustomize` is still attempted.
.. data:: PREFIXES
- A list of prefixes for site package directories
+ A list of prefixes for site-packages directories.
.. versionadded:: 2.6
.. data:: ENABLE_USER_SITE
- Flag showing the status of the user site directory. True means the
- user site directory is enabled and added to sys.path. When the flag
- is None the user site directory is disabled for security reasons.
+ Flag showing the status of the user site-packages directory. ``True`` means
+ that it is enabled and was added to ``sys.path``. ``False`` means that it
+ was disabled by user request (with :option:`-s` or
+ :envvar:`PYTHONNOUSERSITE`). ``None`` means it was disabled for security
+ reasons (mismatch between user or group id and effective id) or by an
+ administrator.
.. versionadded:: 2.6
.. data:: USER_SITE
- Path to the user site directory for the current Python version or None
+ Path to the user site-packages for the running Python. Can be ``None`` if
+ :func:`getusersitepackages` hasn't been called yet. Default value is
+ :file:`~/.local/lib/python{X.Y}/site-packages` for UNIX and non-framework Mac
+ OS X builds, :file:`~/Library/Python/{X.Y}/lib/python/site-packages` for Mac
+ framework builds, and :file:`{%APPDATA%}\\Python\\Python{XY}\\site-packages`
+ on Windows. This directory is a site directory, which means that
+ :file:`.pth` files in it will be processed.
.. versionadded:: 2.6
.. data:: USER_BASE
- Path to the base directory for user site directories
+ Path to the base directory for the user site-packages. Can be ``None`` if
+ :func:`getuserbase` hasn't been called yet. Default value is
+ :file:`~/.local` for UNIX and Mac OS X non-framework builds,
+ :file:`~/Library/Python/{X.Y}` for Mac framework builds, and
+ :file:`{%APPDATA%}\\Python` for Windows. This value is used by Distutils to
+ compute the installation directories for scripts, data files, Python modules,
+ etc. See also :envvar:`PYTHONUSERBASE`.
.. versionadded:: 2.6
-.. envvar:: PYTHONNOUSERSITE
-
- .. versionadded:: 2.6
-
-
-.. envvar:: PYTHONUSERBASE
-
- .. versionadded:: 2.6
-
-
.. function:: addsitedir(sitedir, known_paths=None)
- Adds a directory to sys.path and processes its pth files.
+ Add a directory to sys.path and process its :file:`.pth` files.
+
.. function:: getsitepackages()
- Returns a list containing all global site-packages directories
- (and possibly site-python).
+ Return a list containing all global site-packages directories (and possibly
+ site-python).
.. versionadded:: 2.7
+
.. function:: getuserbase()
- Returns the "user base" directory path.
-
- The "user base" directory can be used to store data. If the global
- variable ``USER_BASE`` is not initialized yet, this function will also set
- it.
+ Return the path of the user base directory, :data:`USER_BASE`. If it is not
+ initialized yet, this function will also set it, respecting
+ :envvar:`PYTHONUSERBASE`.
.. versionadded:: 2.7
+
.. function:: getusersitepackages()
- Returns the user-specific site-packages directory path.
-
- If the global variable ``USER_SITE`` is not initialized yet, this
- function will also set it.
+ Return the path of the user-specific site-packages directory,
+ :data:`USER_SITE`. If it is not initialized yet, this function will also set
+ it, respecting :envvar:`PYTHONNOUSERSITE` and :data:`USER_BASE`.
.. versionadded:: 2.7
-.. XXX Update documentation
-.. XXX document python -m site --user-base --user-site
+The :mod:`site` module also provides a way to get the user directories from the
+command line:
+
+.. code-block:: sh
+
+ $ python3 -m site --user-site
+ /home/user/.local/lib/python3.3/site-packages
+
+.. program:: site
+
+If it is called without arguments, it will print the contents of
+:data:`sys.path` on the standard output, followed by the value of
+:data:`USER_BASE` and whether the directory exists, then the same thing for
+:data:`USER_SITE`, and finally the value of :data:`ENABLE_USER_SITE`.
+
+.. cmdoption:: --user-base
+
+ Print the path to the user base directory.
+
+.. cmdoption:: --user-site
+
+ Print the path to the user site-packages directory.
+
+If both options are given, user base and user site will be printed (always in
+this order), separated by :data:`os.pathsep`.
+
+If any option is given, the script will exit with one of these values: ``O`` if
+the user site-packages directory is enabled, ``1`` if it was disabled by the
+user, ``2`` if it is disabled for security reasons or by an administrator, and a
+value greater than 2 if there is an error.
+
+.. seealso::
+
+ :pep:`370` -- Per user site-packages directory
diff --git a/Doc/tutorial/interactive.rst b/Doc/tutorial/interactive.rst
--- a/Doc/tutorial/interactive.rst
+++ b/Doc/tutorial/interactive.rst
@@ -156,17 +156,18 @@
quotes, etc., would also be useful.
One alternative enhanced interactive interpreter that has been around for quite
-some time is `IPython`_, which features tab completion, object exploration and
+some time is IPython_, which features tab completion, object exploration and
advanced history management. It can also be thoroughly customized and embedded
into other applications. Another similar enhanced interactive environment is
-`bpython`_.
+bpython_.
.. rubric:: Footnotes
.. [#] Python will execute the contents of a file identified by the
:envvar:`PYTHONSTARTUP` environment variable when you start an interactive
- interpreter.
+ interpreter. To customize Python even for non-interactive mode, see
+ :ref:`tut-customize`.
.. _GNU Readline: http://tiswww.case.edu/php/chet/readline/rltop.html
diff --git a/Doc/tutorial/interpreter.rst b/Doc/tutorial/interpreter.rst
--- a/Doc/tutorial/interpreter.rst
+++ b/Doc/tutorial/interpreter.rst
@@ -242,7 +242,29 @@
execfile(filename)
+.. _tut-customize:
+
+The Customization Modules
+-------------------------
+
+Python provides two hooks to let you customize it: :mod:`sitecustomize` and
+:mod:`usercustomize`. To see how it works, you need first to find the location
+of your user site-packages directory. Start Python and run this code:
+
+ >>> import site
+ >>> site.getusersitepackages()
+ '/home/user/.local/lib/python3.2/site-packages'
+
+Now you can create a file named :file:`usercustomize.py` in that directory and
+put anything you want in it. It will affect every invocation of Python, unless
+it is started with the :option:`-s` option to disable the automatic import.
+
+:mod:`sitecustomize` works in the same way, but is typically created by an
+administrator of the computer in the global site-packages directory, and is
+imported before :mod:`usercustomize`. See the documentation of the :mod:`site`
+module for more details.
+
+
.. rubric:: Footnotes
.. [#] A problem with the GNU Readline package may prevent this.
-
diff --git a/Doc/using/cmdline.rst b/Doc/using/cmdline.rst
--- a/Doc/using/cmdline.rst
+++ b/Doc/using/cmdline.rst
@@ -255,7 +255,8 @@
.. cmdoption:: -s
- Don't add user site directory to sys.path
+ Don't add the :data:`user site-packages directory <site.USER_SITE>` to
+ :data:`sys.path`.
.. versionadded:: 2.6
@@ -532,7 +533,8 @@
.. envvar:: PYTHONNOUSERSITE
- If this is set, Python won't add the user site directory to sys.path
+ If this is set, Python won't add the :data:`user site-packages directory
+ <site.USER_SITE>` to :data:`sys.path`.
.. versionadded:: 2.6
@@ -543,7 +545,9 @@
.. envvar:: PYTHONUSERBASE
- Sets the base directory for the user site directory
+ Defines the :data:`user base directory <site.USER_BASE>`, which is used to
+ compute the path of the :data:`user site-packages directory <site.USER_SITE>`
+ and Distutils installation paths for ``python setup.py install --user``.
.. versionadded:: 2.6
--
Repository URL: http://hg.python.org/cpython
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