Author: mark.dickinson Date: Fri Jul 30 15:13:02 2010 New Revision: 83277 Log: Add note about surprising behaviour from round function. Modified: python/branches/py3k/Doc/library/functions.rst Modified: python/branches/py3k/Doc/library/functions.rst ============================================================================== --- python/branches/py3k/Doc/library/functions.rst (original) +++ python/branches/py3k/Doc/library/functions.rst Fri Jul 30 15:13:02 2010 @@ -972,6 +972,13 @@ The return value is an integer if called with one argument, otherwise of the same type as *x*. + .. note:: + + The behavior of :func:`round` for floats can be surprising: for example, + ``round(2.675, 2)`` gives ``2.67`` instead of the expected ``2.68``. + This is not a bug: it's a result of the fact that most decimal fractions + can't be represented exactly as a float. See :ref:`tut-fp-issues` for + more information. .. function:: set([iterable]) :noindex: