PyScript lets you run Python scripts right in the browser, side by side with JavaScript, with two-way interaction between your code and the web page. Created by Anaconda and launched in April 2022 ...

Save that text to a file, open it in a browser and it runs. Well, of course, no server set-up for you. Presumably, the work is being done on the pyscript.net server which takes a lot of set-up!

The uv utility lets you run Python packages and libraries with one command and no setup. Here's the quick guide to running Python packages without installing them.