pyredblack 0.1.0

Red/black trees in C++ for Python

============
pyredblack
============

.. image:: https://travis-ci.org/wroberts/pyredblack.svg?branch=master
:target: https://travis-ci.org/wroberts/pyredblack

Copyright (c) 2015 Will Roberts <[e-mail]>

Licensed under the MIT License (see ``LICENSE.rst`` for details).

Cython interface to red-black trees implemented in C++.

`Red-black trees`_ are a kind of `self-balancing binary tree`_. They
maintain their entries in sorted order and have O(log n) for
insertion, lookup, and deletion. You can read more about red-black
trees `here
<http://www.eternallyconfuzzled.com/tuts/datastructures/jsw_tut_rbtree.aspx>`_
and see animations of insertion, lookup, and deletion `here
<https://www.cs.usfca.edu/~galles/visualization/RedBlack.html>`_.

.. _`Red-black trees`: http://en.wikipedia.org/wiki/Red%E2%80%93black_tree
.. _`self-balancing binary tree`: http://en.wikipedia.org/wiki/Self-balancing_binary_search_tree

This package provides dictionary and set objects based on
red-black-trees; these can be used as drop-in replacements for the
built-in ``dict`` and ``set`` types, except that they maintain their
contents in sorted order.

Dictionary (``rbdict``)::

>>> import pyredblack
>>> d = pyredblack.rbdict(Germany = 'Berlin',
Hungary = 'Budapest',
Ireland = 'Dublin',
Portugal = 'Lisbon',
Cyprus = 'Nicosia',
Greenland = 'Nuuk',
Iceland = 'Reykjavik',
Macedonia = 'Skopje',
Bulgaria = 'Sofia',
Sweden = 'Stockholm')
>>> len(d)
10
>>> d['Ireland']
'Dublin'
>>> d.keys()
['Bulgaria', 'Cyprus', 'Germany', 'Greenland', 'Hungary',
'Iceland', 'Ireland', 'Macedonia', 'Portugal', 'Sweden']
>>> d.values()
['Sofia', 'Nicosia', 'Berlin', 'Nuuk', 'Budapest',
'Reykjavik', 'Dublin', 'Skopje', 'Lisbon', 'Stockholm']
>>> d.popitem()
('Bulgaria', 'Sofia')
>>> d.popitem()
('Cyprus', 'Nicosia')
>>> d.popitem()
('Germany', 'Berlin')

Set (``rbset``)::

>>> fruit = pyredblack.rbset(['apple', 'orange', 'apple', 'pear',
'orange', 'banana'])
>>> 'orange' in fruit
True
>>> 'crabgrass' in fruit
False
>>> a = pyredblack.rbset('abracadabra')
>>> b = pyredblack.rbset('alacazam')
>>> list(a)
['a', 'b', 'c', 'd', 'r']
>>> list(a - b)
['b', 'd', 'r']
>>> list(a | b)
['a', 'b', 'c', 'd', 'l', 'm', 'r', 'z']
>>> list(a & b)
['a', 'c']
>>> list(a ^ b)
['b', 'd', 'l', 'm', 'r', 'z']
>>> a.pop()
'a'
>>> a.pop()
'b'
>>> a.pop()
'c'

Requirements
------------

- Python 2.7, Python 3.2+
- Cython (and a C++ compiler)

Todo
----

- implement slicing on dictionaries