SFragments

Recently at the Austin Functional Programming meetup I gave a presentation on Haskell typeclasses. I based the presentation on the University of Pennsylvania course CIS194, Spring 2013 edition, Homework 5. This course is online and is a good tool for teaching yourself Haskell.http://www.cis.upenn.edu/~cis194/spring13/hw/05-type-classes.pdf. Here is my presentation.

There are many tutorials on how to get started with the Redux pattern in Angular 2, and how to use its essential concepts like store or effects. But often you'll find that those tutorials don't work for you -- maybe the author omitted something that was self-explanatory to them, or maybe (and that's a fact) Redux-related packages in npm change so often that the code in the tutorials from a few months ago does not compile anymore. So let's throw in another tutorial that will be obsolete just as soon, shall we?

(* if you have both Python 2 and Python 3 on your machine. If you only have Python 3, you probably don't need this article.)

I wanted to install Python 3 on Windows 10, and use it in a virtualenv. Eventually I wanted to get my Flask web application to run on Python 3.

The steps for that are not too difficult, but there are a few gotchas along the way. And you know what that means, Gentle Reader. It means that when I have to do it again -- let's say, months from now -- I will have to hunt down the solutions to all the gotchas again. So I decided to take lessons from the past and write it all down. And share it with those of you who don't want waste time hunting down the answers. So, this is what I did.

Let's say you are an ordinary developer, not a wizard at administrating the Apache server. You are looking for a place to host your side project, a Flask application (Flask is a Python web framework). To have the most control at only a small price, you provision a cloud server at your friendly cloud hosting company (Dreamhost, in my case). Perhaps you were not satisfied with free hosting sites, because they give you so little computing power that you quickly max out your available database connections. And so you decide to run it on your own server.

Just to be clear, this article does not deal with production-caliber Flask applications. It describes a minimal, very basic deployment options for simple applications such as your side projects or hobby projects. It does not address, for example, Python virtualenv. Maybe in the future.

Tooltips are a useful thing. Just last year, as a volunteer web developer, I built an event website for a nonprofit. The website had a page with the event program grid. The event had several parallel tracks, each of them jam-packed of back-to-back panels, and each panel had several panelists. Understandably, the web page real estate was at a premium, and the page for the panel grid listed the participants by only their last name. No other info.

My impression of Evernote API documentation is that it is not very friendly to Python beginners, and rather short on examples. So I wrote this document on how to write a simple script that will get notes from a notebook.

These are slides from a lightning talk I gave at Women Who Code (a meetup for women software developers) Austin chapter on January 5, 2015.

The name Larval Mode comes from the Hacker's Dictionary where it means the state of being a novice programmer or techie. The panelists were Eric Raymond and "one of the unsung heroes of the internet" John Quarterman. They did this panel specifically for a group of high school students who travelled to Linucon.

Here are some topics they talked about.

• The old semantic rift between hackers and crackers. What are crackers up to these days? How are they different from the old time crackers? The conversation veered from computer criminals to terrorists, and from there to open source warfare.
• Why is open source software so poorly documented? What's lacking in the open source software documentation: it's not details, it's motivation. Better than a well-documented program: a self-configuring program. How Eric Raymond wrote such a program. During a lull in conversation John Quarterman talks about risk management.
• How did the two famous panelists got where they are today? What are the two paths to fame and ability to influence people? Eric Raymond claims he found the easy path.
• What happens when government mandates new technologies? Knowing Eric Raymond's views, one can easily guess the answer: nothing good.
• Economics of system administrators, and other bundled goods, or why the total cost of ownership of Linux systems is lower than that of Windows systems.
• Disruptive technologies, from transistor radios to internet. Disruptive technologies usually lead to a better product, but not always. For example, blogs are taking away the power from the conventional media sources, but John Quarterman can't help but see the downside of that.

I can't guarantee that I quoted Eric Raymond or John Quarterman correctly, but I tried to capture the essence of what they said.

Recently I was surprised to see that Ruby uniq method didn't seem to work on ActiveRecord. Suppose I have a bunch of ActiveRecords and I want to select just the ones that are unique by some field.