Posted by Jeff December 13, 2007
Recently I came across two Python editing environments, Reinteract and Hotwire. The screencasts could not be more different. It’s instructive to consider what makes a superior screencast.
Before I pontificate, what makes my opinion worth listening to? I have an eye for video - I am a top contributor to VideoSift. My screencasts on ShowMeDo have been well reviewed.
Dislaimer: I know nothing about the two projects beyond having seen these screencasts. Also, Hotwire lead Colin Walters notes that the Hotwire screencast is fan-made; an improved official vid may be in the works.
Let’s deconstruct these examples to figure out: makes a screencast suck or succeed?
Audio
Hotwire uses a hard-rocking song. The soundtrack is irrelevant to the action onscreen, and distracts. Currently a single YouTube comment asks for the song title.
Reinteract is narrated by the developer. He knows his stuff and his clarity of speech conveys precision. The pacing feels right.
Video
Hotwire is presented in what Yahtzee has dubbed TeenyWeenyEyestrainoVision. Youtube’s stingy real estate obliterates detail. Add AutoPanning and Beryl fx for added wooziness.
Reinteract is clean and sharp. No other distracting windows or desktop. Video is full size; details are preserved. The entire screencast takes place in one window. Overall: clean, simple, focused.
Pacing / Narrative
Hotwire has so many distracting elements it’s impossible for an outsider to follow. After 30 seconds of squinting, I gave up. Hotwire may have fantastic features.. this video does not communicate them.
Reinteract has a coherent, well structured progression. The narrator explains features, benefits, and builds complexity. As a viewer I see what makes it cool and useful and how I might apply it
Summary
The purpose of Screencasts is to communicate concepts. Show the Sizzle. Principles of writing apply: dump anything that doesn’t contribute. Audio should be on topic. Video should be sharp, fullscreen, with no distractions. YouTube is a poor choice. Pacing and narrative should set a context, deliver benefits, and communicate something new and useful.
When done right, screencasts can communicate cheaply and effectively to a worldwide audience.
marketing, python, reinteract, screencast
Posted by Jeff May 01, 2007
I’ve been playing with BookMooch’s API recently. They have data files for:
- Inventory : how many copies of each book are moochable
- Wishlists: How many people want each book.
- ASIN’s : full details for each book.
My initial goal is the availability (Inventory-Wishlist) of each book. Examples:
| Availability |
Title |
| -210 |
Omnivore’s Dilemma |
| -172 |
The God Delusion |
| 115 |
The Da Vinci Code |
| 122 |
Jurassic Park |
Omnivore’s Dilemma is in heavy demand; Jurassic Park is a stale meme. The value of a book decreases over time; it makes sense to trade in current books while you can.
ASINS.xml is 983MB; a DOM parser requires far too much memory. A SAX parser is required to handle a file this size.
My requirements are to produce a CSV file mapping ISBN to Title. A pickled version of a python map would also be useful.
ASIN Detail
See example here.
SAX ContentHandler
A ContentHandler is supplied as a callback. The parser calls startElement, characters,and stopElement and as it walks the XML input stream. Since the id element repeats, examining the tag name is insufficient to know the location in the tree. Instead, a list of containing elements makes sense:
class asinHandler(ContentHandler):
def __init__(self):
self.curElements=[] # Will have the path to the current location.
def startElement(self, name, attrs):
self.curElements.append(name)
def endElement(self, name):
self.curElements.pop()
Capturing ID, Title
My only interest is in the title and ID of each book.
def characters(self,ch):
if len(self.curElements) ==3:
if self.curElements == ‘id’:
self.isbn = self.isbn + ch
elif self.curElements[2] == ‘Title’:
self.title = self.title + ch
def startElement(self, name, attrs):
if name==’asin’:
self.isbn = ‘’
self.title = ‘’
def endElement(self, name):
if name==’asin’:
self.br.record ( self.isbn.strip(), self.title.strip() )
Full Program
# IN: asins_fixed.xml
# OUT: isbns.txt, isbns.pickle
# http://www.devarticles.com/c/a/XML/Parsing-XML-with-SAX-and-Python/
import codecs,pickle
from xml.sax import make_parser
from xml.sax.handler import ContentHandler
BOOKNUM = 0
class bookRecorder:
def __init__(self):
# *Very Important* to open in the right encoding!
self.f = codecs.open (’isbns.txt’,'w’, ‘iso-8859-1′)
self.dict = {}
def record(self,isbn,title):
self.f.write(unicode (isbn+’,’ + title +’\r\n’))
self.dict [isbn]=title
def close(self):
self.f.close()
p=open(’isbns.pickle’,'w’,200000)
pickle.dump (self.dict,p)
p.close()
class asinHandler(ContentHandler):
def __init__(self):
self.br=bookRecorder()
self.curElements=[] # Will have the path to the current location.
def characters(self,ch):
if len(self.curElements) ==3:
if self.curElements == ‘id’:
self.isbn = self.isbn + ch
elif self.curElements[2] == ‘Title’:
self.title = self.title + ch
def close(self):
self.br.close()
def startElement(self, name, attrs):
self.curElements.append(name)
if name==’asin’:
self.isbn = ‘’
self.title = ‘’
global BOOKNUM
BOOKNUM = BOOKNUM + 1
if BOOKNUM % 5000 == 0:
print BOOKNUM
def endElement(self, name):
if name==’asin’:
self.br.record ( self.isbn.strip(), self.title.strip() )
self.curElements.pop()
parser = make_parser()
curHandler = asinHandler()
parser.setContentHandler(curHandler)
parser.parse(open(’asins_fixed.xml’))
curHandler.close()
asin, bookmooch, python
Posted by Jeff August 19, 2006
I read the bombshell about Django like everyone else, and want to raise a point: this is a good thing for the python community as a whole. The reason is the Paradox of Choice.
The more funds employers offer their employees in 401(k) retirement plans, the less likely the employees are to invest in any, even though in many cases, failing to do so costs them employer-matching funds of up to several thousand dollars a year.
Here is Prof. Barry Schwartz talking at Google The Paradox of Choice - Why More Is Less (flash). MP4 format - link should work.
django, python
Posted by Jeff August 16, 2006
technical
- Python Challenge - Difficult but fun web challenge. I want to try to finish this..
- lpy.py Literate programming in python - produces HTML docu mixing code, commentary. Very interesting. (but yet another markup to learn)
- NearlyFreeSpeech.net - pay $1/GB as you go - A “major slashdotting” of a site hosted on our service will cost you (on average) about $10, one time. With python,ruby,perl CGI.
silly
dell, python
Posted by Jeff August 15, 2006
Remember the Nod and Python? Well, I’ve been emailing and bothering various Python folks. I’ve learned:
- There is an official python store at CafePress. It’s hard to find, called”pydotorg”.
- Stickers are now available! $3.49
- There are T-shirts, hats, mugs, etc. The shirts on the official store are awfully expensive, I think - the least expensive is $23, before shipping.
Goodstorm is a new site with much lower base prices than CafePress. I’ve created a store there. Without any markup, the python logo shirt is $8.40 for a men’s fitted T.
I’ll be getting a laptop sticker and a couple t-shirts. So if you see a bearded geek around Harvard/Porter square with a python sticker, say Hi 
goodstorm, python
Posted by Jeff August 11, 2006
Here are search plugins for JavaBlogs, Python documentation, or Scroogle. They install in the search box at the top of the Firefox window:
Click to install:
JavaBlogs: search javablogs.com
Python Docs : search python.org/doc
Scroogle : Google results without the cookies or search records.
To uninstall search engines, use SearchPluginHacks. To right-click on text and invoke a search engine, I like SearchWith.
firefox, google, java, javablogs, python, scroogle, search
Posted by Jeff August 04, 2006
Kathy Sierra writes about “The Nod” - the acknowledgement of another person’s good taste in making the same choices as you.
What does this have to do with programming languages? Programmers care deeply about language choice — How do python developers recognize each other? There should be an obvious signifier - like a laptop sticker. The guy on the train might be a MOT (Member of the Tribe), too.
I’ve looked around on cafepress and see a few, but they’re the old logo. I want a sticker with the new logo.
python, thenod
Posted by Jeff July 21, 2006
Hangman - nice lil game built with GWT
JavaAlmanac - switching between too many languages? This site has the snippets you need.
Rubik’s Cube Solving Robot video
Python on the Nokia S60 The geek in me wants this very much.
Fly Guy - Flash game. Strangely relaxing.
SqlObjectGuide : Best tips I’ve found for SQLObject, the Python O/R mapper.
GWT, python, sqlobject
Posted by Jeff July 13, 2006
I’m in vacation, yet here I am on dialup, geeking out. Life moves slower here in the country..so do the downloads.
Textile your textareas with Greasemonkey
wikiPad - wiki app. Now open source. I’ve been using NoteLens for off-the-cuff notetaking, a little walled garden where I don’t have to worry about file names, but I’m jonesing for markup and hyperlinks…wikipad might do the trick.
Lumpy generates UML diagrams from a running Python program - darn, missed the presentation at the Boston Python meetup.
python, textile, uml
Posted by Jeff May 31, 2006
Titus has written a nice intro to nose with examples. I emphatically agree:
the most important part of having unit tests is that they can be run quickly, easily, and without any thought
Thus, I was suprised not to see something like Nosy, to automagically run tests when code changes. To me, running tests by hand requires thought, and a context switch. Nosy keeps me in the flow.
Pinocchio is an extension to filter out long-running tests so tests may be run quickly. This leads me to believe his test suite was too big to run automatically.
(What is it about nose that inspires bad puns? This blog title, nosy, pinocchio…well, what do expect in a language named after comedy troupe
python,unittesting
nose, nosy, python, unit testing
