A Reputable Journal

I’ve seen several interesting blog posts related to MIT switching from Scheme to Python for their intro course. This is really interesting to me since SICP is one of my favorite CS books of all time. Nevertheless I’m glad to see leading institutions change to my favorite language.

Paraphrase of Gerald Sussman’s remarks

Dan Weinreb’s blog

The other day I discovered that the folks working on VPython have been very busy over the last couple of years. I had given up on VPython because the Mac distribution was so difficult to use. It required the X windows server and one point and lots of other extra junk at other times. But now things are easy! There is a great installer package and it just works.

For those of you who have not heard of VPython before it is a 3D graphics module called visual built on top of Python and OpenGL. You can do a lot of nice 3D graphics very simply with VPython. Its great for education in math and physics and introductory computer science.

So as an experiment I built a turtle graphics module on top of VPython. I use turtle graphics a lot in teaching but the TKinter turtles all suffer from some event loop problems when you use them with IDLE. VPython does not suffer from this problem plus gives you a lot of other cool benefits. One of the benefits is that the window resizes automatically for you based on the units you use in your application. Want to draw a picture at the atomic level of detail? No problem, want to draw planets circling each other? Again no problem.

Here’s a screen capture of a fractal tree created in 3-D using my new turtle.

def tree(t,trunkLength):
    if trunkLength < 5:
        return
    else:
        turnDz = random.randint(20,40)
        turnDx = random.randint(20,40)
        trunkShort = random.randint(10,20)
        t.width(trunkLength/10.0)
        if trunkLength < 25:
            t.color(color.green)
        else:
            t.color((174/255.0,145/255.0,0))
        t.forward(trunkLength)
        # right trunk
        t.right(turnDz,ZAXIS)
        tree(t,trunkLength-trunkShort)
        # left trunk
        t.left(2turnDz,ZAXIS)
        tree(t,trunkLength-trunkShort)
        # front trunk
        t.right(turnDz,ZAXIS)
        t.right(turnDx,XAXIS)
        tree(t,trunkLength-trunkShort)
        # back trunk
        t.left(2turnDx,XAXIS)
        tree(t,trunkLength-trunkShort)
        # restore
        t.right(turnDx,XAXIS)
        t.backward(trunkLength)

Here’s a little plug for our book from our Colleague Mark Guzdial at Georgia Tech. This was written last September right after the book was published but I didn’t find out about it until this morning. Thanks Mark!

In addition, David and I have started a new blog to post corrections and updates to Python Programming in Context Over here If you are already using the book please check it out.

Intro

The Code

#!/usr/bin/env python

from rtm import *
import sys
import Growl

def sendNotify(ts):
    if type(ts.task) == list:
        for j in range(len(ts.task)):
            notifier.notify("today","Task Due: "+ts.task[j].due[:10],ts.name,sticky=True)
    else:
        notifier.notify("today","Task Due: "+ts.task.due[:10],ts.name,sticky=True)

if len(sys.argv) == 2:
    command = sys.argv[1]
else:
    command = "today"

apiKey = "get your own"
secret = "this too"
token = "You will create this"

name = "RTMDue"
notifications = ["today","tomorrow"]
notifier = Growl.GrowlNotifier(name,notifications)
notifier.register()

if command[:3] == "tod" or command == '':
    cutoff = 'today'
elif command[:3] == "tom":
    cutoff = 'tomorrow'
else:
    cutoff = None 

rtm = createRTM(apiKey, secret, token)

if cutoff:
    filterString = 'status:incomplete and (due:%s or dueBefore:%s)'%(cutoff,cutoff)
else:
    filterString = 'status:incomplete'

theTasks = rtm.tasks.getList(filter=filterString)

if type(theTasks.tasks.list) == list:
    for i in range(len(theTasks.tasks.list)):
        if type(theTasks.tasks.list[i].taskseries) == list:
            for j in range(len(theTasks.tasks.list[i].taskseries)):
                ts = theTasks.tasks.list[i].taskseries[j]
                sendNotify(ts)
        else:
            ts = theTasks.tasks.list[i].taskseries
            sendNotify(ts)
else:
    if type(theTasks.tasks.list.taskseries) == list:
        for i in range(len(theTasks.tasks.list.taskseries)):
            ts = theTasks.tasks.list.taskseries[i]
            sendNotify(ts)
    else:
        ts = theTasks.tasks.list.taskseries
        sendNotify(ts)

Next Steps