ckanext-scheming 2.1 now support Datasets with repeating subfields and repeating text fields. Repeating subfieds support custom snippets and validation just like regular fields.

This work is inspired by the excellent ckanext-composite extension and replaces ckanext-repeating repeating_text fields.

You must be using CKAN 2.8 or later and a custom IPackageController plugin to index datasets with repeating subfields.

• NumPy Illustrated: The Visual Guide to NumPy
• Half-Precision Floating-Point, Visualized
• Johnny•Decimal
• PostgreSQL index optimizations
• “A Mind is Born” 256-byte demo

Hello! Content from the old excess.org site will be migrated here over the next few months. Thank you for stopping by.

CKAN’s datastore_search now comes with format options and is up to 17x faster.

This article covers:

• new total row calculation
• new result generation
• new record formats

TL;DR:

1. Use CKAN 2.7 or later and resource views and other code that uses datastore_search is faster with no other changes required
2. Update your datastore_search client code to use one of the new records_format=csv and/or include_total=false options to make it much, much faster

I had the pleasure of co-hosting CKANCon last week and presented a short talk on ckanapi and ckanext-scheming.

For pyrf I needed to take data from a frequency plot, which could be any number of points, and present it as a spectrogram that fills the view size exactly. In the spectrogram I only care about the maximum values that appear in the range of frequencies represented by each pixel.

If I could just divide the number of source bins by an integer factor the solution would be simple:

return np.amax(data.reshape((-1, factor)), axis=1)

But I have to be able to handle any number of source bins and output that to any number of pixels.

Fortunately numpy is awesome.

I’ve been working on two new CKAN extensions that I’m really excited about. Since I helped build the custom metadata schema for open.canada.ca/ I’ve never been completely satisfied with the approach we took. These new extensions are the start of a proper solution to the compromises we made.

The new extensions are:

• ckanext-scheming data-driven custom schemas
• ckanext-fluent multilingual text fields

What does bar.foo do? - An exploration of Python assignment, objects, attributes and descriptors

This is a talk I gave March 27, 2014 at the Ottawa Python Authors Group meetup.

Follow along with the IPython notebook version if you would like to play with the code examples.

After working on PyRF this past year, I was asked to help edit to a paper written by ThinkRF’s Nikhil Adnani for AUTOTESTCON 2013: Wideband 20 GHz RF Digitizer and Python-based Open Application Framework for Test and Measurement.

This paper won the Walter E. Peterson award for Best Paper on Technology.

A site I’ve been working on for the past few months has just launched. data.gc.ca “2.0” (update: now open.canada.ca) is a completely rewritten version of the Open Data portal for the Government of Canada.

I worked on the CKAN portion of the site responsible for the data catalogue. CKAN is an open source Data Portal application written in Python. I built a fully bilingual schema with many additional fields for our datasets. I also optimized, fixed and improved many parts of CKAN itself.

Our team built templates based on the Web Experience Toolkit (WET). WET provides building blocks for creating accessible, mobile-friendly web sites. These templates include a map widget for our geospatial datasets and an interactive data table for previews of tabular data.

All of our work is available on the open-data github page and is released under a permissive license.

data.gc.ca might just be the largest, most fully bilingual and most accessible CKAN site anywhere. More to come!

This is something I’ve been wanting to write for a while.

Unicode page U+2800 has all the combinations of a 2x4 grid of Braille dots. Braille dots that line up neatly with the ones on all sides in most fonts. We can paint with this!

This is the second part of the talk I gave January 24, 2013 at the Ottawa Python Authors Group.

Part One introduces Python iterables and iterators and generators. This part covers the advanced use of generators while building an interactive two-player network game.

This is part one of a talk I gave January 24, 2013 at the Ottawa Python Authors Group

Part Two is now also available.

Both parts of this presentation are also available as a single IPython Notebook which you can download and run locally, or view with nbviewer.ipython.org. The complete source is available at https://github.com/wardi/iterables-iterators-generators

Announcing XTerm Colour Chart 2.0 “Old and busted: Colour Cubes. New hotness: Colour Cows” release.

The script has been completely rewritten. It now requires python 2.3 or later for the optparse command-line parsing module.

Many new features have been added to this version:

• Five different charts available in 256 and 88-colour modes
• Origin and rotation of colour cube is now configurable
• Size of colour cells is now configurable
• Colour palette now exactly matches xterm defaults
• Resetting colour palette is now flicker-free
• Source code is much nicer (and commented!)

xterm_colour_chart on github