Using Glitch for Pyramid Learning

At this year’s Jazkarta sprint we decided to invest some time in creating Pyramid learning resources. We are fans of the Pyramid web framework, and we felt that it would be nice to work on something that would make it easier to get started with, especially for novice developers.

Enter Glitch. This is a platform that is designed for letting users explore web apps created by other Glitch users. When you see an application that does something that you want to do, you can “remix” it, which means that an exact copy, with all its code and resources, is created in your own workspace (which is some sort of Docker container). You can then change it in any way you like. This is very powerful, because you get a working application that is hosted for you, and every code change that you make is immediately reflected in the web app page.

This turns out to be really useful for teaching web application development concepts, because students can see the code for the example, read an explanation, and then right away remix the code to try out their changes, which they can see working instantly. No need for setting up a workspace, checking out code, or running a web server. Just try out an idea and see the result right there, or share it with other people. Like “view HTML source” but with code, which is one of Glitch’s goals.

We decided to create a Glitch collection that would showcase a few of Pyramid’s most distinctive features, along with a simple Hello World style tutorial. The first thing was to verify that Pyramid could be installed. Glitch’s main development target is Node.js, but its containers install Python and they allow the user to run pip, so it’s possible to install most PyPI packages including Pyramid. (For those who might be wondering: sorry, Plone is not installable, because it needs system dependencies that are not installed by Glitch.)

Glitch supports a setup file named glitch.json, which is what allowed us to install Pyramid:

{
 "install": "pip3 install --user pyramid",
 "start": "python3 pyramid_app.py"
}

In the json above, you can see that we install Pyramid using pip, and we can add any other dependencies for our project there. We can then use the “start” key to tell Glitch how to start our application.

Once we did that, the only other thing needed was to create our Pyramid app, which in this case uses code directly lifted from the trypyramid.com site:

from wsgiref.simple_server import make_server
from pyramid.config import Configurator
from pyramid.response import Response

def hello_world(request):
    return Response('Hello Glitch')

if __name__ == '__main__':
    with Configurator() as config:
       config.add_route('hello', '/')
       config.add_view(hello_world, route_name='hello')
       app = config.make_wsgi_app()
    server = make_server('0.0.0.0', 3000, app)
    server.serve_forever()

That’s it. Glitch automatically runs the application (the only caveat is that it needs to use port 3000). You can configure it so that any code change automatically restarts the app. After this, if a potential new user sees your project, she can just use the remix button and have a copy made in her workspace. Any change that she makes, like changing the hello text, will be immediately visible on the page.

Overall, we found Glitch to be a very intuitive and easy to use service. You can see the collection of simple tutorials that we created here:

Pyramid Quick Tutorials