AT&T now unlocks iPhones

I just chatted with an AT&T support person through their web site and got my iPhone unlocked (well, I got the support request in, supposedly I’ll get an unlock code by May 8).

Wait, what’s that? … I won the lottery? … Ok, whatever.

AT&T just unlocked my iPhone!

Tracking down potential bug in PyISAPIe

Brushing up on my C skills…

http://stackoverflow.com/questions/9891467/large-post-data-is-corrupted-when-using-django-pyisapie-iis

Resentment

Resentment is what happens when you fail to honor a request that I never made.

Take an encyclopedia with you wherever you go

I’m working on a new project:  Putting 45,000 Wikipedia articles on a USB stick for offline use, e.g. for doing research while traveling on a plane, train, bus or in the car (preferably not while driving).

It’s for sale now at http://www.wikiusb.com/ - check it out!

Shenandoah National Park Oral History Collection

A project I’ve worked on over the last few years is now online at http://mdid.cit.jmu.edu/snp/.  It is a collection of oral history recordings and transcripts, delivered through a custom interface built on MDID3.

See the official announcement at http://www.jmu.edu/jmuweb/general/news/general11933.shtml.

Breaking Twitter Mobile

Udacity CS373 Localization Problem

I’m taking the Udacity CS373 Programming a Robotic Car class.  Below is my solution to the localization homework problem in unit 1 that was due yesterday.  Note that this is not the complete program, just the homework portion.

world_width = len(colors[0])
world_height = len(colors)

p = [[1. / (world_width * world_height)] * world_width
     for i in range(world_height)]

def sense(p, Z):
    q = [
            [
                pcol * (sensor_right if scol == Z else (1 - sensor_right))
                for pcol, scol in zip(prow, crow)
            ]
            for prow, crow in zip(p, colors)
        ]
    norm = sum(sum(row) for row in q)
    return [[col / norm for col in row] for row in q]

def move(p, motion):
    ym, xm = motion
    return [
            [
                p_move * p[(y - ym) % world_height][(x - xm) % world_width]
                + (1 - p_move) * p[y][x]
                for x in range(world_width)
            ]
            for y in range(world_height)
          ]

for me, mo in zip(measurements, motions):
    p = move(p, mo)
    p = sense(p, me)

Instead of looping, I make use of list comprehensions, which I think is a cleaner solution.

Pivotal Tracker

Just started playing with Pivotal Tracker for a side project.

People who say it cannot be done…

People who say it cannot be done should not interrupt those who are doing it.

- George Bernard Shaw

Lazy objects in Django

Working on one of my Django projects, I created a new context processor to populate some template context variables.  One of them was a list of values pulled from the database that was only used on a few pages, so I tried to wrap it in a SimpleLazyObject:

from django.utils.functional import SimpleLazyObject
def current_presentation(request):
    presentation = SimpleLazyObject(lambda: fetch_current_presentation(request.user))
    presentation_records = SimpleLazyObject(lambda: list(presentation.items.values_list('record_id', flat=True).distinct()))
    return {
     'current_presentation': presentation,
     'current_presentation_records': presentation_records,
    }

That unfortunately does not work:

django.template.TemplateSyntaxError
TemplateSyntaxError: Caught TypeError while rendering: argument of type 'SimpleLazyObject' is not iterable

The problem is that the SimpleLazyObject wrapper does not implement an __iter__ method, so a wrapped object that is iterable loses that property.

The fix: a new subclass of SimpleLazyObject:

class IterableLazyObject(SimpleLazyObject):
    def __iter__(self):
        if self._wrapped is None: self._setup()
        return self._wrapped.__iter__()

Done!