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

a lazily evaluated sequence type for Python

Project Description

lazyseq is a simple library implementing a single class, LazySeq, which provides a lazily evaluated sequence that can be used like an immutable list. You can think of it as a Pythonic version of Clojure’s Seq. The main use of LazySeq is for wrapping generators or generator expressions to make them persistent, but still lazy.

LazySeq implements Python’s sequence interface, and thus has the methods __getitem__, __len__, __contains__, __iter__, __reversed__, index, and count.

Getting an item from a LazySeq is equivalent to getting an items from the provided iterable as a list. However, only the necessary elements of the iterable are evaluated (all those up to the maximum requested element), and all evaluated elements are cached on the LazySeq so it can be iterated over again. Note that some operations like len(seq) will by necessity iterate over (and thus cache) the entire iterable.

To use LazySeq, just call LazySeq on any Python iterable:

>>> from lazyseq import LazySeq
>>> seq = LazySeq(x ** 2 for x in range(5))
>>> seq
LazySeq([...])
>>> seq[:3]
[0, 1, 4]
>>> seq
LazySeq([0, 1, 4, ...])
>>> list(seq)
[0, 1, 4, 9, 16]
>>> seq
LazySeq([0, 1, 4, 9, 16])
Release History

Release History

This version
History Node

0.1.1

History Node

0.1.0

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
lazyseq-0.1.1.tar.gz (2.5 kB) Copy SHA256 Checksum SHA256 Source Mar 10, 2014

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