Category Archives: Tutorials

Introduction to Python Courses

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Dear Reader,

I am providing free lectures on intro-to-python.  Salesforce supporting me through their voluntary time off program.  Salesforce.com under it’s 1-1-1 program gives each employee 7 days to work on voluntary projects.

You can find the lectures here:

Lectures

Code

Application Class

The 4th class will be held at Cambridge Innovation Center, 1 Broadway, Cambridge Ma on Saturday November 18th 2017.  They are held every 2nd Saturday afterwards.  Possible projects:

  1. A mini Q/A program.  It introduces the concept of regex using re.
  2. Opening a file in python, reading it’s lines and analyzing words.
  3. Utilizing SimpleHttp server host a basic webpage with <p>, <h1> and <div> tags.  This is a simple introduction to a one-line web server.

The curriculum is free and I encourage people to submit practice problems to the GitHub repository.

Moodle Platform

Moodle is an open-source learning platform. Often, Moodle is used in universities.  I plan on implementing a Moodle instance to host lectures online.

Spammy E-mails, Great!

Moodle implementation has stalled.  I decided to host e-mail service myself.  I did get smtp and e-mail server up.  The obstacle now is getting Google and other e-mail providers to realize my E-mail isn’t spam.

Why is it considered SPAM?

Evidently, you can send an E-mail from chriskottmyer.com, but claim it originated from john smith.com.  Web industry has developed two processes to prevent this: SPF and DKIM.  SPF creates a guarantee that a message from johnsmith.com originates from johnsmith.com.  DKIM encrypts SMTP header preventing snoopers from changing that in transit.

Apache and VPL!

After resolving the spam crisis, I will have to deal with an annoying URL issue.  Moodle loves my IP address.  It loves it so much, it’s bound it to all the URLs.  I don’t like!  I’ll have to make either application-level change or re-route in Apache to resolve.

Having Moodle is great.  It doesn’t support programming assignments out of the box.  Luckily, some wonderful academics invented a plugin called the VPL.  It takes code presented to the web, submits it to a restrictive JVM-based sandbox and runs it.  It should prevent any malicious hackers from hijacking the server (crossing fingers).  It also supports automated grading of coding exercises (yay!).

Both issues aren’t blocking the lectures!  Hopefully everyone can enjoy those!

Best,

Chris

 

Powerful Accessories to Excel – Introduction

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Dear Readers,

I wanted to start a quick tutorial targeted at Excel users and highlighting cool technologies that are relatively easy to learn and can provide a lot of benefit.  Basically, they are technologies that provide a lot of bang for their “effort” bucks.  The technologies I want to cover in order of ease to learn are:

Bash/Batch – Bash and Batch are shells for Linux/Mac and Windows respectively.  Shells interact with your operating system to allow you to do things like read files, manipulate data, create remote login sessions and schedule tasks on your computer.  One of the great things about bash and batch is that if you study it long enough, you can start using “cloud” computers, which allow computers to do work, while you are sleeping.

SQL/RDBMS – Relational databases allow you to store data compactly on your computer and provide a convenient interface for doing data manipulation.  One great reason you should pick up this tool is that it allows you to specify relationships between data: Student – Class -Teacher – School being a good example and then make statements like: I want only class taught by John Naughton that are considered math classes and only students whose first name starts with A.  One great thing about databases is scale.  You can work with 100s of millions of rows. Since SQL is a standard for data access, there are SQL-esque access to big data tools like Hadoop and Spark, which is software that allows you to take dozens of computer and have them process things in parallel.

Python – Python is a general purpose programming language that provides countless libraries for different purposes.  Do you want to develop a website or automate networking?  Python can do this.  Do you want to scrape a website, travel through a social network or do analysis on wikipedia?  Python is a great tool for it.  Do you want to be on the cutting edge of machine learning and AI by having direct interface to more advanced libraries?  Python…  Python can also be used for data manipulation and processing, which I will focus on.

I focus on the above three based on my knowledge.  Other noteworthy technologies include R, which I hope to cover in a future article.  During these tutorials, I might also mention other cool concepts or technologies.

If you are interested in this lecture series, I will put it under tutorial categories.

Best,

Chris