PyScript and my journey to the Web

Slides

The gh-pages branch of this repo contains the slides for PyScript and my journey to the Web. The presentation contents are licensed under CC-BY-4.0. The slides are available at https://sjirwin.github.io/pyscript-journey/ and are rendered using reveal.js via GitHub pages.

Code

The main branch contains code that was written as part of my PyScript journey. Any code in this repo which is authored by me is covered by the MIT license.

The repo does contain some code obtained from open source projects (e.g., PyScript). Any such code is covered by the original projects' licenses.

Direct Dependancies

• PyScript
• Pyodide
• Flask

Code Layout

• hello_world : a very basic "Hello World" web page implemented using PyScript. You should be able to load this directly into your browser via File -> Open (i.e., no web server should be needed). An internet connection is required since the page will dynamically download PyScript and Pyodide. Pyodide in particular is quite large (281 Mb as of this writing) so if you are not blessed with a fast internet connection, the page might take some time to load and render.
• flask-hello_world : a trivial Flask app used to verify that Flask is installed correctly.
• server : the main Flask app. This has been configured to use a local, static copy of PyScript and Pyodide. The PyScript files are included in this repo and reside in server/static/pyscript (these were copied from pyscript.net/alpha on 2022-Aug-07). Given its size, Pyodide is not included and must be downloaded from its releases page (details below).

Web Server Set Up

I used Python 3.10 during development. However any modern, supported version of Python should work ("Your milage may vary").

Install in a virtual environment

• Create a virtual environment and install Flask (assumes pip is installed)

python3.10 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

Verify that the web server works

• Test that the web server is installed and works on localhost

cd flask-hello_world
flask run --port 5050 # avoid standard port

• Check that the flask app works on localhost

Pyodide and PyScript as static resources

• PyScript : as mentioned above, the PyScript files are included in this repo. They reside in server/static/pyscript
• Pyodide : because of its size, Pyodide is not included and must be downloaded from its releases page. The code in this repo assumes version 0.21 (I used 0.21.1).
  • Download version 0.21.1 from the GitHub releases page
  • Unpack the tar.bz2 file
  • Move the pyodide directory to server/static
• Verify that everything is working
  • Start the server (assumes venv is still active)

cd server
flask run

• Load the hello page from localhost

Run the mortgage calculator

• If you are able to load the hello page, then the mortgage calulator app should also be loadable
  • Load the mortgage app from localhost