Note that you cannot use web workers on an HTML file loaded locally; you must load it from a web server that provides certain headers. PyScript’s documentation explains how this works in detail.

The new PyScript project lets you embed Python programs directly in HTML pages and execute them within the browser without any server-based requirements.

We’ll look at three Python web frameworks that follow this paradigm, allowing you to describe front-end code (HTML, CSS, and JavaScript) using back-end Python code.