Snow sprint report #4 : a new command in zc.buildout + a context-free grammar text generator

So this was the last sprint day here at the snowsprint, and a lot of work was done to wrap-up some of the tasks. On my side I worked on two topics:

• adding a new describe command to zc.buildout
• coding a random-text generator library

Adding a “describe” command to zc.buildout

Godefroid came up with a nice idea about buildouts: when you are working with a recipe, it’s sometimes hard to figure out what are the options it takes, which ones are optionals, what are the default, etc.

It means that you have to digg into the code, or get to the PyPI page. Hopefully this page will give you the infos, if the long_description variable was hooked into some reSTructuredText. (see iw.recipe.pound for example).

That make a lot of context changes for the developer, so basically, the idea of the new describe command is to be able to query for a given recipe help. This help will be displayed online as long as the recipe creator fills the Recipe class docstring. We checked with Jim that this would be a good idea, since he wants (and that’s good) to keep the recipe as simple as possible (basically, any class with an install and an update commands). Since he liked the idea, we started to code it.

So basically, the command is called like this:

    $ bin/buildout describe my.recipes
    my.recipes
        The coolest recipe on Earth.
        Ever.

It deals with recipe versions and takes care of multiple entry points:

    $ bin/buildout describe my.recipes:default my.recipes:second
    my.recipes:default
        The coolest recipe on Earth.
        Ever.
    my.recipes:second
        No description available

This feature looks quite simple, but was a bit tricky to implement, since we had to parse the working set of the current buildout to extract the infos. The version section is also taken care of.

All that work we did together with Godefroid and Dokai is in a branch, waiting for Jim’s feedback.

Coding a random-text generator

When we worked on benchmarking Solr versus Plain catalog on the indexing task, we created a small script to generate random text, based on a chomsky algorithm. We were really excited about going deeper in this topic. Both Dokai and I worked on some generators. I have written on my side a Python port of nonsense, and the results were pretty interesting.

Anyway, we started a fun task for the last day with Dokai and Ethan: write a random-text generator library and a grok-based web app on the top of it. I worked on the core part, and we came up with this cool command line scripts that would generate som random text, given a file that would provide structure of sentences, and for each part of the sentence a list of choices.

The command is building the sentences picking the choices randomly. For example this file adapted from nonsense (extract):

[gibberish]

default =
    ${course}

name = college

annoucement =
    The ${university} class "${course}" has been cancelled due to lack of interest.
    Starting next year, incoming freshman at ${university} will be required to take "${course}."
    "${course}" will no longer be offered at ${university} due to lack of interest.
    Due to overwhelming popularity, an additional section of "${course}" will be offered at ${university} next semester.
    Not one single student signed up for ${university}'s "${course}" last semester.

course =
    ${adjective} ${noun} ${suffix}
    ${adjective} ${noun}: ${ending}
    ${adjective} ${noun} And ${adjective} ${noun} ${suffix}
    ${noun} & ${noun} ${suffix}
    ${group1} ${group2} ${life} ${suffix}
    ${group2} ${noun} ${life} ${suffix}
    ${group1} ${group2} ${life} Since {#1800-1970}
    ${group2} ${life}: ${ending}
 event =
    The African Diaspora
    The Harlem Renaissance
    The Civil Rights Movement
    The Italian Renaissance
    Westward Expansion
    Manifest Destiny
    Women's Suffrage
    World War I
    World War II
    The War Of 1812
    The American Revolution
    The French Revolution
    The Russian Revolution
    The American Civil War
    The Spanish-American War
    The Franco-Prussian War
    The JFK Assasination

action =
    Basketweaving
    Aquatic Ballet
    Synchronized Swimming
    Professional Sports
    The ${adjective} Pottery Experience
    Home Economics
    Cardplaying
    Birdwatching

noun =
    Diversity
    Globalism
 ...

will generate random, domain-specific text. A Grok application has been built on the top on this, allowing dynamic creation of such files, and online text generation. Check out Dokai’s blog about this during the week, as he will present the Grok part. The code is in a Git repo here: http://repo.or.cz/w/gibberis.ch.git

Thank you Lovely Systems

Thanks to the Lovely team for this sprint !

Filed under: plone, python, zope