[New-bugs-announce] [issue17100] rotating an ordereddict

[Antoine Pitrou]

New submission from Antoine Pitrou:

It can be useful to rotate an OrderedDict (for example when managing a circular playlist). I haven't found any efficient way to do so from user code, without poking at the internals.

Actually, I envision three methods:

 OrderedDict.rotate(self, n):

   rotate n steps to the right (similarly to deque.rotate())

 OrderedDict.rotate_at(self, key):

   rotate so that the given key ends up in first position

 OrderedDict.rotate_after(self, key):

   rotate so that the given key ends up in last position

(rotate_at, rotate_after could be merged in a single method with a "last" argument, if deemed more elegant)

Note: another solution to the playlist problem would be to have insert_after() and insert_before() methods.

----------
messages: 181086
nosy: pitrou, rhettinger
priority: normal
severity: normal
status: open
title: rotating an ordereddict
type: enhancement
versions: Python 3.4

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue17100>
_______________________________________