Smith College Guest Lecture, "How to build a simple production web site in Python"

Last week I had a fun gig giving a one-hour guest lecture for Smith College's freshman Intro Computer Science through Programming class. The topic was "How to build a simple production web site in Python" in which I was invited to share the process and technology that went into building PeepWeather.com . The rationale was that it would give the students a taste of what is possible to create using some relatively straightforward Python frameworks and libraries, hopefully providing some motivation for those wondering what good their current and (necessarily) bounded assignments are.

I had a great time meeting the challenge of putting together a presentation that had breadth and was motivating, but at the same time understandable to the audience (with a the right amount of stretching to keep them engaged). It went well, with some excellent questions during and after the talk. Here I want to share a little about the concepts and technology I covered in case you're considering giving a similar presentation of your own site. For the curious, here's the PowerPoint as a PDF (unfortunately the video did not work out).

Technologies

I named these technologies, describing each pretty briefly, except for diving deeper into Flask:

• Python web apps: Flask, standard web tech (HTML, CSS, cookies, JavaScript), and the common JavaScript libraries: jQuery for sanity, Bootstrap for layout, and typeahead.js for autocompletion.
• Application-specific: XML and REST (for the weather.gov API), Pillow for the widget image, PyEphem for the daylight calculation, and Weather Icons.
• Deployment: Heroku for hosting, Git for pushing, gunicorn for Flask on Heroku, and Namecheap.com for domain registration.

Concepts

I covered the following at various levels of detail:

• Web frameworks (routing, templates)
• The Model-View-Controller design pattern (and design patterns in general)
• Object-oriented design using Class-Responsibility-Collaborator cards
• Test-driven development
• User interface design

The Code

I jumped into the code at the appropriate points, folding as needed so I didn't overwhelm. I stuck to high level basics, highlighting the concepts they currently know including classes and methods. Mainly the focus was on how the concepts got implemented in Python, but no significant code detail; there simply wasn't time. (Note that IntelliJ IDEA's presentation mode worked great for the projector.)

Motivation

I tried to make two points to get the students excited. First, they are programmers and so they have a powerful skill to create web sites! I suggested they pay attention to any thoughts that come up like "Wouldn't it be great if you could __?" or "Why isn't there a site to __?" Second, I pointed out that putting together even a small site is a fantastic portfolio piece that impresses prospective employers. It shows that they can have ideas and, better yet, bring them into reality on their own. I wrapped up by saying that I had a ton of fun writing PeepWeather and learning the various technologies. It's extremely gratifying to bring something into reality (if that's the right word for something as virtual as a web site :-)

Overall I enjoyed both the talk's preparation and presentation, and I hope to give it at the other Five Colleges.