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  r83732 | mark.dickinson | 2010-08-04 19:42:43 +0100 (Wed, 04 Aug 2010) | 3 lines

  Issue #9498:  Add reference to sys.float_info from 'numeric types' docs.
  Thanks Yitz Gale.
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Mark Dickinson 2010-08-04 18:48:34 +00:00
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Doc/library/stdtypes.rst
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@ -224,18 +224,20 @@ Numeric Types --- :class:`int`, :class:`float`, :class:`long`, :class:`complex`
pair: C; language
There are four distinct numeric types: :dfn:`plain integers`, :dfn:`long
integers`, :dfn:`floating point numbers`, and :dfn:`complex numbers`. In
integers`, :dfn:`floating point numbers`, and :dfn:`complex numbers`. In
addition, Booleans are a subtype of plain integers. Plain integers (also just
called :dfn:`integers`) are implemented using :ctype:`long` in C, which gives
them at least 32 bits of precision (``sys.maxint`` is always set to the maximum
plain integer value for the current platform, the minimum value is
``-sys.maxint - 1``). Long integers have unlimited precision. Floating point
numbers are implemented using :ctype:`double` in C. All bets on their precision
are off unless you happen to know the machine you are working with.
Complex numbers have a real and imaginary part, which are each implemented using
:ctype:`double` in C. To extract these parts from a complex number *z*, use
``z.real`` and ``z.imag``.
``-sys.maxint - 1``). Long integers have unlimited precision. Floating point
numbers are usually implemented using :ctype:`double` in C; information about
the precision and internal representation of floating point numbers for the
machine on which your program is running is available in
:data:`sys.float_info`. Complex numbers have a real and imaginary part, which
are each a floating point number. To extract these parts from a complex number
*z*, use ``z.real`` and ``z.imag``. (The standard library includes additional
numeric types, :mod:`fractions` that hold rationals, and :mod:`decimal` that
hold floating-point numbers with user-definable precision.)
.. index::
pair: numeric; literals