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-rw-r--r--Doc/library/sys.rst137
1 files changed, 77 insertions, 60 deletions
diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index 0e4adec..96450c5 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -235,14 +235,13 @@ always available.
.. data:: flags
- The struct sequence *flags* exposes the status of command line flags. The
- attributes are read only.
+ The :term:`struct sequence` *flags* exposes the status of command line
+ flags. The attributes are read only.
============================= =============================
attribute flag
============================= =============================
:const:`debug` :option:`-d`
- :const:`division_warning` :option:`-Q`
:const:`inspect` :option:`-i`
:const:`interactive` :option:`-i`
:const:`optimize` :option:`-O` or :option:`-OO`
@@ -262,15 +261,18 @@ always available.
.. versionadded:: 3.2.3
The ``hash_randomization`` attribute.
+ .. versionchanged:: 3.3
+ Removed obsolete ``division_warning`` attribute.
+
.. data:: float_info
- A structseq holding information about the float type. It contains low level
- information about the precision and internal representation. The values
- correspond to the various floating-point constants defined in the standard
- header file :file:`float.h` for the 'C' programming language; see section
- 5.2.4.2.2 of the 1999 ISO/IEC C standard [C99]_, 'Characteristics of
- floating types', for details.
+ A :term:`struct sequence` holding information about the float type. It
+ contains low level information about the precision and internal
+ representation. The values correspond to the various floating-point
+ constants defined in the standard header file :file:`float.h` for the 'C'
+ programming language; see section 5.2.4.2.2 of the 1999 ISO/IEC C standard
+ [C99]_, 'Characteristics of floating types', for details.
+---------------------+----------------+--------------------------------------------------+
| attribute | float.h macro | explanation |
@@ -520,8 +522,9 @@ always available.
.. data:: hash_info
- A structseq giving parameters of the numeric hash implementation. For
- more details about hashing of numeric types, see :ref:`numeric-hash`.
+ A :term:`struct sequence` giving parameters of the numeric hash
+ implementation. For more details about hashing of numeric types, see
+ :ref:`numeric-hash`.
+---------------------+--------------------------------------------------+
| attribute | explanation |
@@ -556,8 +559,8 @@ always available.
This is called ``hexversion`` since it only really looks meaningful when viewed
as the result of passing it to the built-in :func:`hex` function. The
- struct sequence :data:`sys.version_info` may be used for a more human-friendly
- encoding of the same information.
+ :term:`struct sequence` :data:`sys.version_info` may be used for a more
+ human-friendly encoding of the same information.
The ``hexversion`` is a 32-bit number with the following layout:
@@ -585,8 +588,8 @@ always available.
.. data:: int_info
- A struct sequence that holds information about Python's
- internal representation of integers. The attributes are read only.
+ A :term:`struct sequence` that holds information about Python's internal
+ representation of integers. The attributes are read only.
+-------------------------+----------------------------------------------+
| Attribute | Explanation |
@@ -641,9 +644,13 @@ always available.
.. data:: maxunicode
- An integer giving the largest supported code point for a Unicode character. The
- value of this depends on the configuration option that specifies whether Unicode
- characters are stored as UCS-2 or UCS-4.
+ An integer giving the value of the largest Unicode code point,
+ i.e. ``1114111`` (``0x10FFFF`` in hexadecimal).
+
+ .. versionchanged:: 3.3
+ Before :pep:`393`, ``sys.maxunicode`` used to be either ``0xFFFF``
+ or ``0x10FFFF``, depending on the configuration option that specified
+ whether Unicode characters were stored as UCS-2 or UCS-4.
.. data:: meta_path
@@ -718,36 +725,35 @@ always available.
This string contains a platform identifier that can be used to append
platform-specific components to :data:`sys.path`, for instance.
- For most Unix systems, this is the lowercased OS name as returned by ``uname
- -s`` with the first part of the version as returned by ``uname -r`` appended,
- e.g. ``'sunos5'``, *at the time when Python was built*. Unless you want to
- test for a specific system version, it is therefore recommended to use the
- following idiom::
+ For Unix systems, except on Linux, this is the lowercased OS name as
+ returned by ``uname -s`` with the first part of the version as returned by
+ ``uname -r`` appended, e.g. ``'sunos5'`` or ``'freebsd8'``, *at the time
+ when Python was built*. Unless you want to test for a specific system
+ version, it is therefore recommended to use the following idiom::
if sys.platform.startswith('freebsd'):
# FreeBSD-specific code here...
elif sys.platform.startswith('linux'):
# Linux-specific code here...
- .. versionchanged:: 3.2.2
- Since lots of code check for ``sys.platform == 'linux2'``, and there is
- no essential change between Linux 2.x and 3.x, ``sys.platform`` is always
- set to ``'linux2'``, even on Linux 3.x. In Python 3.3 and later, the
- value will always be set to ``'linux'``, so it is recommended to always
- use the ``startswith`` idiom presented above.
-
For other systems, the values are:
- ====================== ===========================
- System :data:`platform` value
- ====================== ===========================
- Linux (2.x *and* 3.x) ``'linux2'``
- Windows ``'win32'``
- Windows/Cygwin ``'cygwin'``
- Mac OS X ``'darwin'``
- OS/2 ``'os2'``
- OS/2 EMX ``'os2emx'``
- ====================== ===========================
+ ================ ===========================
+ System :data:`platform` value
+ ================ ===========================
+ Linux ``'linux'``
+ Windows ``'win32'``
+ Windows/Cygwin ``'cygwin'``
+ Mac OS X ``'darwin'``
+ OS/2 ``'os2'``
+ OS/2 EMX ``'os2emx'``
+ ================ ===========================
+
+ .. versionchanged:: 3.3
+ On Linux, :attr:`sys.platform` doesn't contain the major version anymore.
+ It is always ``'linux'``, instead of ``'linux2'`` or ``'linux3'``. Since
+ older Python versions include the version number, it is recommended to
+ always use the ``startswith`` idiom presented above.
.. seealso::
@@ -764,7 +770,7 @@ always available.
independent Python files are installed; by default, this is the string
``'/usr/local'``. This can be set at build time with the ``--prefix``
argument to the :program:`configure` script. The main collection of Python
- library modules is installed in the directory :file:`{prefix}/lib/python{X.Y}``
+ library modules is installed in the directory :file:`{prefix}/lib/python{X.Y}`
while the platform independent header files (all except :file:`pyconfig.h`) are
stored in :file:`{prefix}/include/python{X.Y}`, where *X.Y* is the version
number of Python, for example ``3.2``.
@@ -806,11 +812,11 @@ always available.
the interpreter loads extension modules. Among other things, this will enable a
lazy resolving of symbols when importing a module, if called as
``sys.setdlopenflags(0)``. To share symbols across extension modules, call as
- ``sys.setdlopenflags(ctypes.RTLD_GLOBAL)``. Symbolic names for the
- flag modules can be either found in the :mod:`ctypes` module, or in the :mod:`DLFCN`
- module. If :mod:`DLFCN` is not available, it can be generated from
- :file:`/usr/include/dlfcn.h` using the :program:`h2py` script. Availability:
- Unix.
+ ``sys.setdlopenflags(os.RTLD_GLOBAL)``. Symbolic names for the flag modules
+ can be found in the :mod:`os` module (``RTLD_xxx`` constants, e.g.
+ :data:`os.RTLD_LAZY`).
+
+ Availability: Unix.
.. function:: setprofile(profilefunc)
@@ -1003,22 +1009,33 @@ always available.
to a console and Python apps started with :program:`pythonw`.
-.. data:: subversion
+.. data:: thread_info
- A triple (repo, branch, version) representing the Subversion information of the
- Python interpreter. *repo* is the name of the repository, ``'CPython'``.
- *branch* is a string of one of the forms ``'trunk'``, ``'branches/name'`` or
- ``'tags/name'``. *version* is the output of ``svnversion``, if the interpreter
- was built from a Subversion checkout; it contains the revision number (range)
- and possibly a trailing 'M' if there were local modifications. If the tree was
- exported (or svnversion was not available), it is the revision of
- ``Include/patchlevel.h`` if the branch is a tag. Otherwise, it is ``None``.
+ A :term:`struct sequence` holding information about the thread
+ implementation.
- .. deprecated:: 3.2.1
- Python is now `developed <http://docs.python.org/devguide/>`_ using
- Mercurial. In recent Python 3.2 bugfix releases, :data:`subversion`
- therefore contains placeholder information. It is removed in Python
- 3.3.
+ +------------------+---------------------------------------------------------+
+ | Attribute | Explanation |
+ +==================+=========================================================+
+ | :const:`name` | Name of the thread implementation: |
+ | | |
+ | | * ``'nt'``: Windows threads |
+ | | * ``'os2'``: OS/2 threads |
+ | | * ``'pthread'``: POSIX threads |
+ | | * ``'solaris'``: Solaris threads |
+ +------------------+---------------------------------------------------------+
+ | :const:`lock` | Name of the lock implementation: |
+ | | |
+ | | * ``'semaphore'``: a lock uses a semaphore |
+ | | * ``'mutex+cond'``: a lock uses a mutex |
+ | | and a condition variable |
+ | | * ``None`` if this information is unknown |
+ +------------------+---------------------------------------------------------+
+ | :const:`version` | Name and version of the thread library. It is a string, |
+ | | or ``None`` if these informations are unknown. |
+ +------------------+---------------------------------------------------------+
+
+ .. versionadded:: 3.3
.. data:: tracebacklimit