What is the best ordered dict implementation in python?

python dictionary ordereddictionary
Josh Gibson picture Josh Gibson · Apr 5, 2009 · Viewed 7.4k times · Source

I've seen (and written) a number of implementations of this. Is there one that is considered the best or is emerging as a standard?

What I mean by ordered dict is that the object has some concept of the order of the keys in it, similar to an array in PHP.

odict from PEP 372 seems like a strong candidate, but it's not totally clear that it is the winner.

Answer

sah picture sah · Jan 8, 2010

This one by Raymond Hettinger is a drop-in substitute for the collections.OrderedDict that will appear in Python 2.7: http://pypi.python.org/pypi/ordereddict

The dev version of the collections docs say it's equivalent to what will be in Python 2.7, so it's probably pretty likely to be a smooth transition to the one that will come with Python.

I've put it in PyPI, so you can install it with easy_install ordereddict, and use it like so:

from ordereddict import OrderedDict
d = OrderedDict([("one", 1), ("two", 2)])

Related questions

Rename a dictionary key

Is there a way to rename a dictionary key, without reassigning its value to a new name and removing the old name key; and without iterating through dict key/value? In case of OrderedDict, do the same, while keeping that …

Read More
Accessing items in an collections.OrderedDict by index

Lets say I have the following code: import collections d = collections.OrderedDict() d['foo'] = 'python' d['bar'] = 'spam' Is there a way I can access the items in a numbered manner, like: d(0) #foo's Output d(1) #bar's Output

Read More
Right way to initialize an OrderedDict using its constructor such that it retains order of initial data?

What's the correct way to initialize an ordered dictionary (OD) so that it retains the order of initial data? from collections import OrderedDict # Obviously wrong because regular dict loses order d = OrderedDict({'b':2, 'a':1}) # An OD is represented by a …

Read More