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svn+ssh://pythondev@svn.python.org/python/trunk ........ r59606 | georg.brandl | 2007-12-29 11:57:00 +0100 (Sat, 29 Dec 2007) | 2 lines Some cleanup in the docs. ........ r59611 | martin.v.loewis | 2007-12-29 19:49:21 +0100 (Sat, 29 Dec 2007) | 2 lines Bug #1699: Define _BSD_SOURCE only on OpenBSD. ........ r59612 | raymond.hettinger | 2007-12-29 23:09:34 +0100 (Sat, 29 Dec 2007) | 1 line Simpler documentation for itertools.tee(). Should be backported. ........ r59613 | raymond.hettinger | 2007-12-29 23:16:24 +0100 (Sat, 29 Dec 2007) | 1 line Improve docs for itertools.groupby(). The use of xrange(0) to create a unique object is less obvious than object(). ........ r59620 | christian.heimes | 2007-12-31 15:47:07 +0100 (Mon, 31 Dec 2007) | 3 lines Added wininst-9.0.exe executable for VS 2008 Integrated bdist_wininst into PCBuild9 directory ........ r59621 | christian.heimes | 2007-12-31 15:51:18 +0100 (Mon, 31 Dec 2007) | 1 line Moved PCbuild directory to PC/VS7.1 ........ r59622 | christian.heimes | 2007-12-31 15:59:26 +0100 (Mon, 31 Dec 2007) | 1 line Fix paths for build bot ........ r59623 | christian.heimes | 2007-12-31 16:02:41 +0100 (Mon, 31 Dec 2007) | 1 line Fix paths for build bot, part 2 ........ r59624 | christian.heimes | 2007-12-31 16:18:55 +0100 (Mon, 31 Dec 2007) | 1 line Renamed PCBuild9 directory to PCBuild ........
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Built-in Constants
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==================
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A small number of constants live in the built-in namespace. They are:
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.. note::
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:data:`None`, :data:`False`, :data:`True` and :data:`__debug__` cannot be
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reassigned (assignments to them raise :exc:`SyntaxError`), so they can be
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considered "true" constants.
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.. XXX False, True, None are keywords too
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.. data:: False
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The false value of the :class:`bool` type. Assignments to ``False``
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are illegal and raise a :exc:`SyntaxError`.
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.. data:: True
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The true value of the :class:`bool` type. Assignments to ``True``
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are illegal and raise a :exc:`SyntaxError`.
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.. data:: None
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The sole value of :attr:`types.NoneType`. ``None`` is frequently used to
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represent the absence of a value, as when default arguments are not passed to a
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function. Assignments to ``None`` are illegal and raise a :exc:`SyntaxError`.
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.. data:: NotImplemented
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Special value which can be returned by the "rich comparison" special methods
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(:meth:`__eq__`, :meth:`__lt__`, and friends), to indicate that the comparison
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is not implemented with respect to the other type.
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.. data:: Ellipsis
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The same as ``...``. Special value used mostly in conjunction with extended
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slicing syntax for user-defined container data types, as in ::
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.. XXX Someone who understands extended slicing should fill in here.
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.. data:: __debug__
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This constant is true if Python was not started with an :option:`-O` option.
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Assignments to :const:`__debug__` are illegal and raise a :exc:`SyntaxError`.
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See also the :keyword:`assert` statement.
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