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authorChristian Heimes <christian@cheimes.de>2008-02-11 06:19:17 (GMT)
committerChristian Heimes <christian@cheimes.de>2008-02-11 06:19:17 (GMT)
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svn+ssh://pythondev@svn.python.org/python/trunk ........ r60701 | georg.brandl | 2008-02-09 22:36:15 +0100 (Sat, 09 Feb 2008) | 2 lines Needs only 2.4 now. ........ r60702 | georg.brandl | 2008-02-09 22:38:54 +0100 (Sat, 09 Feb 2008) | 2 lines Docs are rst now. ........ r60703 | georg.brandl | 2008-02-09 23:00:00 +0100 (Sat, 09 Feb 2008) | 2 lines Fix link. ........ r60704 | georg.brandl | 2008-02-10 00:09:25 +0100 (Sun, 10 Feb 2008) | 2 lines Fix for newest doctools. ........ r60709 | raymond.hettinger | 2008-02-10 08:21:09 +0100 (Sun, 10 Feb 2008) | 1 line Clarify that decimal also supports fixed-point arithmetic. ........ r60710 | nick.coghlan | 2008-02-10 08:32:52 +0100 (Sun, 10 Feb 2008) | 1 line Add missing NEWS entry for r60695 ........ r60712 | mark.dickinson | 2008-02-10 15:58:38 +0100 (Sun, 10 Feb 2008) | 3 lines Turn classmethods into staticmethods, and avoid calling the constructor of subclasses of Rational. (See discussion in issue #1682.) ........ r60715 | mark.dickinson | 2008-02-10 16:19:58 +0100 (Sun, 10 Feb 2008) | 2 lines Typos in decimal comment and documentation ........ r60716 | skip.montanaro | 2008-02-10 16:31:54 +0100 (Sun, 10 Feb 2008) | 2 lines Get the saying right. ;-) ........ r60717 | skip.montanaro | 2008-02-10 16:32:16 +0100 (Sun, 10 Feb 2008) | 2 lines whoops - revert ........ r60718 | mark.dickinson | 2008-02-10 20:23:36 +0100 (Sun, 10 Feb 2008) | 2 lines Remove reference to Rational ........ r60719 | raymond.hettinger | 2008-02-10 21:35:16 +0100 (Sun, 10 Feb 2008) | 1 line Complete an open todo on pickletools -- add a pickle optimizer. ........ r60721 | mark.dickinson | 2008-02-10 22:29:51 +0100 (Sun, 10 Feb 2008) | 3 lines Rename rational.Rational to fractions.Fraction, to avoid name clash with numbers.Rational. See issue #1682 for related discussion. ........ r60722 | christian.heimes | 2008-02-11 03:26:22 +0100 (Mon, 11 Feb 2008) | 1 line The test requires the network resource ........ r60723 | mark.dickinson | 2008-02-11 04:11:55 +0100 (Mon, 11 Feb 2008) | 3 lines Put an extra space into the repr of a Fraction: Fraction(1, 2) instead of Fraction(1,2). ........
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+
+:mod:`fractions` --- Rational numbers
+====================================
+
+.. module:: fractions
+ :synopsis: Rational numbers.
+.. moduleauthor:: Jeffrey Yasskin <jyasskin at gmail.com>
+.. sectionauthor:: Jeffrey Yasskin <jyasskin at gmail.com>
+.. versionadded:: 2.6
+
+
+The :mod:`fractions` module defines an immutable, infinite-precision
+Rational number class.
+
+
+.. class:: Fraction(numerator=0, denominator=1)
+ Fraction(other_fraction)
+ Fraction(string)
+
+ The first version requires that *numerator* and *denominator* are
+ instances of :class:`numbers.Integral` and returns a new
+ ``Fraction`` representing ``numerator/denominator``. If
+ *denominator* is :const:`0`, raises a :exc:`ZeroDivisionError`. The
+ second version requires that *other_fraction* is an instance of
+ :class:`numbers.Fraction` and returns an instance of
+ :class:`Rational` with the same value. The third version expects a
+ string of the form ``[-+]?[0-9]+(/[0-9]+)?``, optionally surrounded
+ by spaces.
+
+ Implements all of the methods and operations from
+ :class:`numbers.Rational` and is immutable and hashable.
+
+
+.. method:: Fraction.from_float(flt)
+
+ This classmethod constructs a :class:`Fraction` representing the
+ exact value of *flt*, which must be a :class:`float`. Beware that
+ ``Fraction.from_float(0.3)`` is not the same value as ``Rational(3,
+ 10)``
+
+
+.. method:: Fraction.from_decimal(dec)
+
+ This classmethod constructs a :class:`Fraction` representing the
+ exact value of *dec*, which must be a
+ :class:`decimal.Decimal`.
+
+
+.. method:: Fraction.__floor__()
+
+ Returns the greatest :class:`int` ``<= self``. Will be accessible
+ through :func:`math.floor` in Py3k.
+
+
+.. method:: Fraction.__ceil__()
+
+ Returns the least :class:`int` ``>= self``. Will be accessible
+ through :func:`math.ceil` in Py3k.
+
+
+.. method:: Fraction.__round__()
+ Fraction.__round__(ndigits)
+
+ The first version returns the nearest :class:`int` to ``self``,
+ rounding half to even. The second version rounds ``self`` to the
+ nearest multiple of ``Fraction(1, 10**ndigits)`` (logically, if
+ ``ndigits`` is negative), again rounding half toward even. Will be
+ accessible through :func:`round` in Py3k.
+
+
+.. seealso::
+
+ Module :mod:`numbers`
+ The abstract base classes making up the numeric tower.
+