From c4fbcdc4c80eb733f923b1c9a5a5c52399acb958 Mon Sep 17 00:00:00 2001 From: Mark Dickinson Date: Fri, 30 Jul 2010 13:13:02 +0000 Subject: [PATCH] Add note about surprising behaviour from round function. --- Doc/library/functions.rst | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst index 8a413f4bc8..5c21f34a3f 100644 --- a/Doc/library/functions.rst +++ b/Doc/library/functions.rst @@ -972,6 +972,13 @@ are always available. They are listed here in alphabetical order. 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: -- 2.50.1