From: Raymond Hettinger Date: Fri, 14 Dec 2007 21:51:50 +0000 (+0000) Subject: Add usage note X-Git-Tag: v2.6a1~863 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e846f38c77f08dba5efd5497d28c741434153a69;p=python Add usage note --- diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst index d782c6927d..771310d00f 100644 --- a/Doc/library/collections.rst +++ b/Doc/library/collections.rst @@ -488,6 +488,14 @@ two additonal methods and a read-only attribute. >>> Pixel(11, 22, 128, 255, 0) Pixel(x=11, y=22, red=128, green=255, blue=0)' +To retrieve a field whose name is stored in a string, use the :func:`getattr` +function: + +:: + + >>> getattr(p, 'x') + 11 + Since a named tuple is a regular Python class, it is easy to add or change functionality. For example, the display format can be changed by overriding the :meth:`__repr__` method: @@ -496,8 +504,8 @@ the :meth:`__repr__` method: >>> Point = namedtuple('Point', 'x y') >>> Point.__repr__ = lambda self: 'Point(%.3f, %.3f)' % self - >>> Point(x=10, y=20) - Point(10.000, 20.000) + >>> Point(x=11, y=22) + Point(11.000, 22.000) Default values can be implemented by starting with a prototype instance and customizing it with :meth:`_replace`: