e-huned.com

extract links from craigslist rdf feeds with python

huned — Thu, 03 Jul 2008 04:52:00 +0000

note the use of urlfetch — i’m using this in an app engine application.

from BeautifulSoup import BeautifulSoup

class RDF(dict):
  def __init__(self, url):
    try:
      self['contents'] = BeautifulSoup(urlfetch.fetch(url).contents)
    except:
      self['contents'] = ”
  def links(self):
    [ item['rdf:about'] for item in self['contents'].findAll(’item’) ] 

if __name__ == ‘__main__’
  from __main__ import RDF
  url = ‘http://sfbay.craigslist.org/search/apa/sfc?format=rss&bedrooms=2&s=0&maxAsk=3000′
  print RDF(url).links

problems with google app engine

huned — Thu, 03 Jul 2008 04:14:11 +0000

if you’re just getting started with app engine, you’ll encounter limitations, some more debilitating than others. i’ll keep a list of those i encounter.

currently, you can’t import urllib2. you’re limited to using urlfetch. urlfetch is decent, but you’d have to re-write/tweak parts of existing libraries that use the ubiquitious urllib2. for example, say goodbye to using the Universal Feed Parser without significant hacking. in the interim, i’m able to use a slightly hacked copy of BeautifulSoup to suck down a feed and parse it out. (2008-07-02, see issue 61)
if your requests are running for a while, you’ll get an google3.apphosting.runtime.DeadlineExceededError exception. this isn’t anything new in the world of the internet, but app engine seems to be a little less lenient in allowing slower code. i think this is a good thing, overall, because it forces you to make web apps that aren’t sucky. (2008-07-03)
difficult to get sane URLs if you’re referring to a single object because str(db.Model.key()) is so awfully long. i actually want some kind of short-ish id with which to build permalinks. but, now, that’s yet *another* thing i have to write code for. how annoying. (2005-07-04)
i can’t use db.ReferenceProperty() with one of my custom classes. I have to db.ReferenceProperty(db.Key), which is ok. but gross. (2008-07-05)
the handlers are pretty basic. maybe that’s good. but i find myself having to decorate handlers with richer functionality so i can write more succint higher-level code. (2008-07-05)
python. i find it limiting in comparison to ruby. maybe i’m still a bit green with it.

nil.nil? # => false

huned — Wed, 02 Jul 2008 00:16:51 +0000

this is good if you’re sadist. (never, ever do this if you work with me.)

class NilClass
 def nil?
   false
 end
end

(via conversation with visnu. he has more.)

is that string a number? (in ruby)

huned — Mon, 30 Jun 2008 21:35:09 +0000

sometimes it’s nice to determine if the content of a String is numeric. String#to_i and String#to_f don’t really help because they’ll silently coerce stuff into zero (e.g., “huned”.to_i # => 0). so here’s a little thing i built a long time ago. i updated it today to handle commas and parenthesis, which are often used in financial data.

class Regexp
  NUMERIC = Regexp.union(%r{^-?\d{1,3}(,\d{3}|\d+)*(\.\d+)*$},
    %r{^\(?\d{1,3}(,\d{3}|\d+)*(\.\d+)*\)?$})
end

class String
  def numeric?
    match(Regexp::NUMERIC) != nil
  end
end

examples!

“1.234″.numeric? # => true
“1,234,567″.numeric? # => true
“1,234,567.23583″.numeric? # => true
“1234567″.numeric? # => true
“(1,234)”.numeric? # => true
“-1,234″.numeric? # => true
etc

it works, but i’m not totally happy with the regular expression. who has a better one?

the nimble start-up

huned — Thu, 26 Jun 2008 17:38:53 +0000

you are the nimble start-up. so, why not spend your energy on top notch product development? without that, sales, marketing, support, strategic hiring, are all for naught. for now, just concentrate on building unequivocal value. do it quickly, because yesterday is already gone.

use the flickr api with javascript

huned — Mon, 16 Jun 2008 22:12:25 +0000

flickr api with javascript, originally uploaded by hunedx.

proxying the flickr api

huned — Sun, 15 Jun 2008 19:40:32 +0000

proxying the flickr api, originally uploaded by hunedx.

today, i have eaten…

huned — Fri, 13 Jun 2008 22:32:11 +0000

thus far…

a smallish homemade cookie
a coffee on the way to work
green tea x 2
a safeway cookie from the work kitchen
earl grey tea

i should be hungry, but i’m not at all.

faster scriptaculous visual effects by default

huned — Fri, 13 Jun 2008 16:03:47 +0000

if you think the default visual effects for scriptaculous are too painfully slow, use this chunk of code to speed it up. (from visnu.

if (typeof(Effect) != "undefined" && Effect.DefaultOptions) {
  // speed up animations
  Effect.DefaultOptions.duration = 0.2;
}

commodities

huned — Wed, 11 Jun 2008 14:50:45 +0000

had this saved on my computer, but moving it here.

commodities

undifferentiated. you buy based on price.
characterized by me-too products, overcapacity, price wars
drucker: “In a commodity market, you can only be as good as your dumbest competitor.”

commodity products

airline seats
RAM
gasoline

danger of commmoditization

harder to build revenue stream
harder to invest in innovation
customer base prone to churn

solutions against commoditization?

innovate
bundle
segment - find customers who are less sensitive to high prices (e.g., lock a multinational into an expensive multi-year contract)

so, if you find yourself building a commodity product it would make sense to step back and revisit some of your assumptions about who your customers are, what their needs are, and why they’ll buy from you as opposed to brand x. (and, no, lower cost doesn’t count unless it’s something obscene like an order of magnitude — but even then, how do you scale your business up?)