symbian-qemu-0.9.1-12/python-2.6.1/Doc/library/constants.rst
author johnathan.white@2718R8BGH51.accenture.com
Mon, 08 Mar 2010 18:45:03 +0000
changeset 46 b6935a90ca64
parent 1 2fb8b9db1c86
permissions -rw-r--r--
Modify framebuffer and NGA framebuffer to read screen size from board model dtb file. Optimise memory usuage of frame buffer Add example minigui application with hooks to profiler (which writes results to S:\). Modified NGA framebuffer to run its own dfc queue at high priority

Built-in Constants
==================

A small number of constants live in the built-in namespace.  They are:


.. data:: False

   The false value of the :class:`bool` type.

   .. versionadded:: 2.3


.. data:: True

   The true value of the :class:`bool` type.

   .. versionadded:: 2.3


.. data:: None

   The sole value of :attr:`types.NoneType`.  ``None`` is frequently used to
   represent the absence of a value, as when default arguments are not passed to a
   function.

   .. versionchanged:: 2.4
      Assignments to ``None`` are illegal and raise a :exc:`SyntaxError`.


.. data:: NotImplemented

   Special value which can be returned by the "rich comparison" special methods
   (:meth:`__eq__`, :meth:`__lt__`, and friends), to indicate that the comparison
   is not implemented with respect to the other type.


.. data:: Ellipsis

   Special value used in conjunction with extended slicing syntax.

   .. XXX Someone who understands extended slicing should fill in here.


.. data:: __debug__

   This constant is true if Python was not started with an :option:`-O` option.
   Assignments to :const:`__debug__` are illegal and raise a :exc:`SyntaxError`.
   See also the :keyword:`assert` statement.


Constants added by the :mod:`site` module
-----------------------------------------

The :mod:`site` module (which is imported automatically during startup, except
if the :option:`-S` command-line option is given) adds several constants to the
built-in namespace.  They are useful for the interactive interpreter shell and
should not be used in programs.

.. data:: quit([code=None])
          exit([code=None])

   Objects that when printed, print a message like "Use quit() or Ctrl-D
   (i.e. EOF) to exit", and when called, raise :exc:`SystemExit` with the
   specified exit code, and when .

.. data:: copyright
          license
          credits

   Objects that when printed, print a message like "Type license() to see the
   full license text", and when called, display the corresponding text in a
   pager-like fashion (one screen at a time).