Skip to main content
This is a pre-production deployment of Warehouse. Changes made here affect the production instance of PyPI (
Help us improve Python packaging - Donate today!

A pure Python skiplist.

Project Description

A pure Python skiplist implementation.

A skiplist provides a quickly searchable structure (like a balanced binary tree) that also updates fairly cheaply (no nasty rebalancing acts). In other words, it’s awesome.

See for more information.

Written mostly an exercise for myself, it turns out skiplists are really useful. It also comes with a (mostly-underdocumented) linked-list implementation (+ a sorted variant), if that’s useful.


  • Python 3.3+ (should work on Python 2.6+ as well, as well as PyPy 2.0+)
  • nose>=1.30 for running unittests


Using it looks like:

>>> import skiplist
>>> skip = skiplist.Skiplist()
>>> len(skip)
>>> 6 in skip
>>> skip.insert(0)
>>> skip.insert(7)
>>> skip.insert(3)
>>> skip.insert(6)
>>> skip.insert(245)
>>> len(skip)
>>> 6 in skip
>>> skip.remove(245)
>>> len(skip)
>>> skip.find(3)
<Skiplist: 3>


Performance is alright, though I’m sure there’s room for improvement. See the script for more information.

Running Tests

Run pip install nose (preferrably within a virtualenv) to install nose.

Then run nosetests -s -v to exercise the full suite.


  • A more performant implementation of remove (still O(N))

  • More performance testing

    • Loading data seems slow


author:Daniel Lindsley
Release History

Release History

This version
History Node


Download Files

Download Files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

File Name & Checksum SHA256 Checksum Help Version File Type Upload Date
pyskip-0.9.0-py2.py3-none-any.whl (6.1 kB) Copy SHA256 Checksum SHA256 2.7 Wheel Dec 3, 2013
pyskip-0.9.0.tar.gz (5.2 kB) Copy SHA256 Checksum SHA256 Source Oct 17, 2013

Supported By

WebFaction WebFaction Technical Writing Elastic Elastic Search Pingdom Pingdom Monitoring Dyn Dyn DNS Sentry Sentry Error Logging CloudAMQP CloudAMQP RabbitMQ Heroku Heroku PaaS Kabu Creative Kabu Creative UX & Design Fastly Fastly CDN DigiCert DigiCert EV Certificate Rackspace Rackspace Cloud Servers DreamHost DreamHost Log Hosting