From c53c9666f57b83ac0430ce6ca480b58e011e96ea Mon Sep 17 00:00:00 2001 From: Georg Brandl Date: Tue, 4 Sep 2007 17:58:02 +0000 Subject: [PATCH] Add a dict view usage example. --- Doc/library/stdtypes.rst | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/Doc/library/stdtypes.rst b/Doc/library/stdtypes.rst index 7ec0180023a..75db75c3502 100644 --- a/Doc/library/stdtypes.rst +++ b/Doc/library/stdtypes.rst @@ -1906,6 +1906,36 @@ to another dictionary view or a set): four operations will fail if an involved dictionary contains such a value. +An example of dictionary view usage:: + + >>> dishes = {'eggs': 2, 'sausage': 1, 'bacon': 1, 'spam': 500} + >>> keys = dishes.keys() + >>> values = dishes.values() + + >>> # iteration + >>> n = 0 + >>> for val in values: + ... n += val + >>> print(n) + 504 + + >>> # keys and values are iterated over in the same order + >>> list(keys) + ['eggs', 'bacon', 'sausage', 'spam'] + >>> list(values) + [2, 1, 1, 500] + + >>> # view objects are dynamic and reflect dict changes + >>> del dishes['eggs'] + >>> del dishes['sausage'] + >>> list(keys) + ['spam', 'bacon'] + + >>> # set operations + >>> keys & {'eggs', 'bacon', 'salad'} + {'eggs', 'bacon'} + + .. _bltin-file-objects: File Objects