Atlas7

How to find out when the mouse been eating my KitKat? A Mouse Detector built with Light Sensor and LEDs - just another fun project using Intel Edison Board, Arduino, Groove Light Sensor, Groove LEDs. See link below for NodeJS Script (to be run via Intel XDK IoT IDE).

I essentially started from the Groove LED script template and Groove Light Sensor script template, and combined the two ideas together. And we have a Light-sensor triggering LEDs mechanism! :)

See this YouTube demo.

/*jslint node:true, vars:true, bitwise:true, unparam:true */
/*jshint unused:true */
// Leave the above lines for propper jshinting

Atlas7

Quick JavaScript demo:

• parsing function as an argument
• assigning a function as a variable (essentially making a copy of the function under a different name)

function sumIt (a, b) {
	console.log("sumIt...")
	return a + b;
};

Atlas7

Learnt a new type of syntax around function today, so thought I would make a quick note here!

The following two examples are equivalent:

Example 1

var i = 1;
console.log( function (j) {return j+100} (i) ) ;
// return 101

Atlas7

Dan Rodney has some great Mac shortcuts at his blog here. Below are some of my favorites.

shortcut	description
cmd + tab	switch apps
cmd + alt + left/right arrow	switch tab within an app
cmd + ` (backtick)	switch windows within the same app

Atlas7

Some sample scripts to demo parsing XML with Python minidom library. Taken from the Udacity Web Development Course - this lesson.

Unknown:apps johnny$ ipython
Python 2.7.10 |Anaconda 2.4.0 (x86_64)| (default, Oct 19 2015, 18:31:17) 
Type "copyright", "credits" or "license" for more information.

IPython 4.0.0 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.

Atlas7

Some simple iPython scripts to illustrate the use of Python urllib2 library. e.g. to interact with the web.

Unknown:apps johnny$ ipython
Python 2.7.10 |Anaconda 2.4.0 (x86_64)| (default, Oct 19 2015, 18:31:17) 
Type "copyright", "credits" or "license" for more information.

IPython 4.0.0 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.

Atlas7

Some examples of JSON escaping in Python (use double back slashes within a string, or single slash within a raw string):

In [1]: import json

In [9]: json.loads('{"story":"oh \\"my\\" word!"}')
Out[9]: {u'story': u'oh "my" word!'}

In [10]: json.loads(r'{"story":"oh \"my\" word!"}')
Out[10]: {u'story': u'oh "my" word!'}

Atlas7

Two ways to load JSON in Python - taken from this video Udacity - Web Development video:

In [14]: json.loads(r'{"story":"once upon a time"}')
Out[14]: {u'story': u'once upon a time'}

In [12]: json.dumps({"story":"once upon a time"})
Out[12]: '{"story": "once upon a time"}'

Atlas7

Here is a nice and simple Python code illustrating a simple implementation of caching - taken from Udacity - Web Development - Caching. i.e. given the same inputs, the computation is only performed once. Some benefits of this approach: (1) reduce load on server, (2) reduce number of read/write against database, (3) faster queries.

# Code

import time

# complex_computation() simulates a slow function. time.sleep(n) causes the
# program to pause for n seconds. In real life, this might be a call to a
# database, or a request to another web service.

Atlas7

Some notes / blog posts relating to Udacity - Web Development course.

Blog Posts

• Udacity – Web Development – Install Google App Engine
• Udacity – Web Development – Hashing
• Udacity – Web Development – Interact the web with Python urllib2
• Udacity – Web Development – API – Parse XML with Python minidom library
• Udacity – Web Development – Escaping JSON in Python
• [Udacity – Web Development – Simple Cached Computation – Python Code](http://mathalope.co.uk/2016/01/17/udacity-web-development-simple-cached-computation-python