Merged revisions 83732 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  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.
........

Doc/library/stdtypes.rst

@@ -230,12 +230,14 @@ 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``.
+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