cyordereddict 0.2

=============
cyordereddict
=============

.. image:: https://travis-ci.org/shoyer/cyordereddict.svg?branch=master
:target: https://travis-ci.org/shoyer/cyordereddict

The Python standard library's ``OrderedDict`` ported to Cython. A drop-in
replacement that is 2-6x faster.

Install:
``pip install cyordereddict``

Dependencies:
CPython (2.6, 2.7, 3.3 or 3.4) and a C compiler. Cython is only required
for the dev version.

Use:
.. code-block:: python

from cyordereddict import OrderedDict

Benchmarks:
Python 2.7:

================== ================================= =========================
Test Code Ratio (stdlib / cython)
================== ================================= =========================
``__init__`` empty ``OrderedDict()`` 1.8
``__init__`` list ``OrderedDict(list_data)`` 4.8
``__init__`` dict ``OrderedDict(dict_data)`` 4.6
``__setitem__`` ``ordereddict[0] = 0`` 8.6
``__getitem__`` ``ordereddict[0]`` 3
``update`` ``ordereddict.update(dict_data)`` 5.5
``__iter__`` ``list(ordereddict)`` 5.6
``items`` ``ordereddict.items()`` 5.9
``__contains__`` ``0 in ordereddict`` 2.3
================== ================================= =========================

Python 3.4:

================== ================================= =========================
Test Code Ratio (stdlib / cython)
================== ================================= =========================
``__init__`` empty ``OrderedDict()`` 1.5
``__init__`` list ``OrderedDict(list_data)`` 3.9
``__init__`` dict ``OrderedDict(dict_data)`` 4.2
``__setitem__`` ``ordereddict[0] = 0`` 8.4
``__getitem__`` ``ordereddict[0]`` 2.9
``update`` ``ordereddict.update(dict_data)`` 6.5
``__iter__`` ``list(ordereddict)`` 2.3
``items`` ``list(ordereddict.items())`` 2.1
``__contains__`` ``0 in ordereddict`` 2.3
================== ================================= =========================
To run these yourself, use ``cyordereddict.benchmark()``

Cavaets:
``cyorderedddict.OrderedDict`` is an extension type (similar to the
built-in ``dict``) instead of a Python class. This is necessary for speed,
but means that in a few pathological cases its behavior will defer from
``collections.OrderedDict``:

* The ``inspect`` module does not work on ``cyorderedddict.OrderedDict``
methods.
* Extension types use slots instead of dictionaries, so you cannot add
custom attributes without making a subclass (e.g.,
``OrderedDict.foo = 'bar'`` will fail).

You can do anything else you might do with an OrderedDict, including
subclassing: everything else passes the ``collections.OrderedDict`` test
suite. We based the Cython code directly on the Python standard library,
and thus use separate code bases for Python 2 and 3, specifically to
reduce the potential for introducing new bugs.

License:
MIT. Based on the Python standard library, which is under the Python
Software Foundation License.