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svn+ssh://pythondev@svn.python.org/python/trunk ........ r59666 | christian.heimes | 2008-01-02 19:28:32 +0100 (Wed, 02 Jan 2008) | 1 line Made vs9to8 Unix compatible ........ r59669 | guido.van.rossum | 2008-01-02 20:00:46 +0100 (Wed, 02 Jan 2008) | 2 lines Patch #1696. Don't attempt to close None in dry-run mode. ........ r59671 | jeffrey.yasskin | 2008-01-03 03:21:52 +0100 (Thu, 03 Jan 2008) | 6 lines Backport PEP 3141 from the py3k branch to the trunk. This includes r50877 (just the complex_pow part), r56649, r56652, r56715, r57296, r57302, r57359, r57361, r57372, r57738, r57739, r58017, r58039, r58040, and r59390, and new documentation. The only significant difference is that round(x) returns a float to preserve backward-compatibility. See http://bugs.python.org/issue1689. ........ r59672 | christian.heimes | 2008-01-03 16:41:30 +0100 (Thu, 03 Jan 2008) | 1 line Issue #1726: Remove Python/atof.c from PCBuild/pythoncore.vcproj ........ r59675 | guido.van.rossum | 2008-01-03 20:12:44 +0100 (Thu, 03 Jan 2008) | 4 lines Issue #1700, reported by Nguyen Quan Son, fix by Fredruk Lundh: Regular Expression inline flags not handled correctly for some unicode characters. (Forward port from 2.5.2.) ........ r59676 | christian.heimes | 2008-01-03 21:23:15 +0100 (Thu, 03 Jan 2008) | 1 line Added math.isinf() and math.isnan() ........ r59677 | christian.heimes | 2008-01-03 22:14:48 +0100 (Thu, 03 Jan 2008) | 1 line Some build bots don't compile mathmodule. There is an issue with the long definition of pi and euler ........ r59678 | christian.heimes | 2008-01-03 23:16:32 +0100 (Thu, 03 Jan 2008) | 2 lines Modified PyImport_Import and PyImport_ImportModule to always use absolute imports by calling __import__ with an explicit level of 0 Added a new API function PyImport_ImportModuleNoBlock. It solves the problem with dead locks when mixing threads and imports ........ r59679 | christian.heimes | 2008-01-03 23:32:26 +0100 (Thu, 03 Jan 2008) | 1 line Added copysign(x, y) function to the math module ........
This commit is contained in:
Christian Heimes
parent
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32 changed files with 383 additions and 83 deletions
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@ -915,10 +915,13 @@ available. They are listed here in alphabetical order.
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.. function:: round(x[, n])
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Return the floating point value *x* rounded to *n* digits after the decimal
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point. If *n* is omitted, it defaults to zero. The result is a floating point
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number. Values are rounded to the closest multiple of 10 to the power minus
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*n*; if two multiples are equally close, rounding is done away from 0 (so. for
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example, ``round(0.5)`` is ``1.0`` and ``round(-0.5)`` is ``-1.0``).
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point. If *n* is omitted, it defaults to zero. Values are rounded to the
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closest multiple of 10 to the power minus *n*; if two multiples are equally
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close, rounding is done toward the even choice (so, for example, both
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``round(0.5)`` and ``round(-0.5)`` are ``0``, and ``round(1.5)`` is
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``2``). Delegates to ``x.__round__(n)``.
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.. versionchanged:: 2.6
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.. function:: set([iterable])
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@ -1064,6 +1067,14 @@ available. They are listed here in alphabetical order.
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operators such as ``super(C, self)[name]``.
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.. function:: trunc(x)
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Return the :class:`Real` value *x* truncated to an :class:`Integral` (usually
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a long integer). Delegates to ``x.__trunc__()``.
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.. versionadded:: 2.6
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.. function:: tuple([iterable])
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Return a tuple whose items are the same and in the same order as *iterable*'s
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@ -26,8 +26,17 @@ Number-theoretic and representation functions:
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.. function:: ceil(x)
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Return the ceiling of *x* as a float, the smallest integer value greater than or
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equal to *x*.
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Return the ceiling of *x* as a float, the smallest integer value greater than
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or equal to *x*. If *x* is not a float, delegates to ``x.__ceil__()``, which
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should return an :class:`Integral` value.
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.. function:: copysign(x, y)
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Return *x* with the sign of *y*. ``copysign`` copies the sign bit of an IEEE
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754 float, ``copysign(1, -0.0)`` returns *-1.0*.
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..versionadded:: 2.6
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.. function:: fabs(x)
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@ -37,8 +46,9 @@ Number-theoretic and representation functions:
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.. function:: floor(x)
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Return the floor of *x* as a float, the largest integer value less than or equal
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to *x*.
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Return the floor of *x* as a float, the largest integer value less than or
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equal to *x*. If *x* is not a float, delegates to ``x.__floor__()``, which
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should return an :class:`Integral` value.
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.. function:: fmod(x, y)
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@ -64,6 +74,23 @@ Number-theoretic and representation functions:
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apart" the internal representation of a float in a portable way.
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.. function:: isinf(x)
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Checks if the float *x* is positive or negative infinite.
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..versionadded:: 2.6
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.. function:: isnan(x)
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Checks if the float *x* is a NaN (not a number). NaNs are part of the
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IEEE 754 standards. Operation like but not limited to ``inf * 0``,
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``inf / inf`` or any operation involving a NaN, e.g. ``nan * 1``, return
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a NaN.
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..versionadded:: 2.6
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.. function:: ldexp(x, i)
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Return ``x * (2**i)``. This is essentially the inverse of function
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99
Doc/library/numbers.rst
Normal file
99
Doc/library/numbers.rst
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@ -0,0 +1,99 @@
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:mod:`numbers` --- Numeric abstract base classes
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================================================
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.. module:: numbers
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:synopsis: Numeric abstract base classes (Complex, Real, Integral, etc.).
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The :mod:`numbers` module (:pep:`3141`) defines a hierarchy of numeric abstract
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base classes which progressively define more operations. These concepts also
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provide a way to distinguish exact from inexact types. None of the types defined
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in this module can be instantiated.
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.. class:: Number
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The root of the numeric hierarchy. If you just want to check if an argument
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*x* is a number, without caring what kind, use ``isinstance(x, Number)``.
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Exact and inexact operations
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----------------------------
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.. class:: Exact
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Subclasses of this type have exact operations.
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As long as the result of a homogenous operation is of the same type, you can
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assume that it was computed exactly, and there are no round-off errors. Laws
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like commutativity and associativity hold.
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.. class:: Inexact
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Subclasses of this type have inexact operations.
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Given X, an instance of :class:`Inexact`, it is possible that ``(X + -X) + 3
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== 3``, but ``X + (-X + 3) == 0``. The exact form this error takes will vary
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by type, but it's generally unsafe to compare this type for equality.
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The numeric tower
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-----------------
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.. class:: Complex
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Subclasses of this type describe complex numbers and include the operations
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that work on the builtin :class:`complex` type. These are: conversions to
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:class:`complex` and :class:`bool`, :attr:`.real`, :attr:`.imag`, ``+``,
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``-``, ``*``, ``/``, :func:`abs`, :meth:`conjugate`, ``==``, and ``!=``. All
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except ``-`` and ``!=`` are abstract.
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.. attribute:: Complex.real
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Abstract. Retrieves the :class:`Real` component of this number.
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.. attribute:: Complex.imag
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Abstract. Retrieves the :class:`Real` component of this number.
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.. method:: Complex.conjugate()
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Abstract. Returns the complex conjugate. For example, ``(1+3j).conjugate() ==
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(1-3j)``.
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.. class:: Real
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To :class:`Complex`, :class:`Real` adds the operations that work on real
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numbers.
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In short, those are: a conversion to :class:`float`, :func:`trunc`,
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:func:`round`, :func:`math.floor`, :func:`math.ceil`, :func:`divmod`, ``//``,
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``%``, ``<``, ``<=``, ``>``, and ``>=``.
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Real also provides defaults for :func:`complex`, :attr:`Complex.real`,
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:attr:`Complex.imag`, and :meth:`Complex.conjugate`.
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.. class:: Rational
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Subtypes both :class:`Real` and :class:`Exact`, and adds
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:attr:`Rational.numerator` and :attr:`Rational.denominator` properties, which
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should be in lowest terms. With these, it provides a default for
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:func:`float`.
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.. attribute:: Rational.numerator
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Abstract.
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.. attribute:: Rational.denominator
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Abstract.
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.. class:: Integral
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Subtypes :class:`Rational` and adds a conversion to :class:`long`, the
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3-argument form of :func:`pow`, and the bit-string operations: ``<<``,
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``>>``, ``&``, ``^``, ``|``, ``~``. Provides defaults for :func:`float`,
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:attr:`Rational.numerator`, and :attr:`Rational.denominator`.
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@ -6,16 +6,18 @@ Numeric and Mathematical Modules
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********************************
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The modules described in this chapter provide numeric and math-related functions
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and data types. The :mod:`math` and :mod:`cmath` contain various mathematical
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functions for floating-point and complex numbers. For users more interested in
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decimal accuracy than in speed, the :mod:`decimal` module supports exact
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representations of decimal numbers.
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and data types. The :mod:`numbers` module defines an abstract hierarchy of
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numeric types. The :mod:`math` and :mod:`cmath` modules contain various
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mathematical functions for floating-point and complex numbers. For users more
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interested in decimal accuracy than in speed, the :mod:`decimal` module supports
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exact representations of decimal numbers.
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The following modules are documented in this chapter:
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.. toctree::
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numbers.rst
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math.rst
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cmath.rst
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decimal.rst
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