Archive for December, 2011

Boggle at the London Python Dojo

(Yes, that is a deliberately ambiguous title offering two possible interpretations: as a description of what the programming challenge was at last night’s Dojo; or as an imperative to be awed at the might and wonder that is the London Python Dojo. You choose).

Last night was the first time I’ve actually run the London Dojo. For the two and more years since its inception, Nicholas Tollervey (@ntoll to his Twitter friends & acquaintances) has indefatigably turned up every first Thursday to clear up the Fry-IT offices, order the pizza, buy the beer, put up signs, leave out sticky labels, request free books from O’Reilly and then drum up support, keep everyone happy and actually run the show, finishing off by organising everyone to clear up, move chairs, dump the rubbish outside, and finally catch the last train home to Sticksville, Northants. where his wife and children have long ago fallen asleep over their sheet music, having gone da Capo al Segno one time too many waiting for him to return home.

A few months ago, Nicholas asked for volunteers to help out, and a small group of us got together to share the burden. Since then, Bruce, Jonathan, Tom and finally I have taken a turn at organising. And of course it’s not until you have to do it yourself that you realise how much work is involved… I was fortunate because Gautier (who actually works there) and Nicholas himself were both at Fry-IT for the day and were able to do some of the less proximate preparation, including ordering a dozen pizzas and buying three dozen bottles of beer. I was able to make a small contribution in the shape of a pack of sticky labels.

The Dojo itself was very slightly quieter than usual: just under 20 rather than just under 30. That’s not a bad thing in Fry’s offices which are not huge. There was a bit of an introduce-yourself session (which was made even more primary-school-like by the presence of big sticky labels on everyone’s chest with their names or cognomens). And then we had a lightning talk from Martin who has a sort of cut-down Nagios for app developers. (I hope I haven’t done it an injustice). And then a surprisingly straightforward vote on the evening’s programming challenge which gave us… Boggle. (Word game; 8×8 grid of random letters; form words by moving like a chess king).

Four teams; four solutions, all more or less different. Only one team ended up with a working solution at the end of 90 minutes (and they appeared to be optimising by removing all vertical whitespace; or maybe that was an aesthetic choice - who knows?). Our team had visible activity (which is more than Team 1 managed!) but no solution. It’s up to each team how they want to manage their collaboration. We’d gone for the split-team approach, dividing the problem into its eminently decoupled parts: a mechanism to read in a dictionary of words and provide efficient searchability (using a Trie, in case you’re interested); and a structure to hold the board (a dictionary, keyed on coordinates), generate the letters into the grid, and search for all possible words, relying on the dictionary code to indicate success, failure, partial success, or success with more possibilities.

The tweets were still flying this morning as people tried to tweak their solution (or, indeed, get it to work at all) on the train, on their phone or at home overnight. A friend of mine who’s a C++ coder came along mainly because I’d talked so much about the Dojo. He’s not really into Python - in fact he’s not really a programmer: he does medical image analysis. But he enjoyed the atmosphere and made a few small suggestions before simply sitting back and watching the teams get to work.

Look out for the next Dojo at the beginning of January. It’ll be announced on the python-uk mailing list and we’ll tweet about it when we’ve fixed a date.

UPDATE Dirk’s added a blog post of his own:
http://elazungu.wordpress.com/2011/12/02/solving-boggle-with-python/