PyScript: Run Python in your HTML (opens in new tab)

https://anvil.works/blog/python-in-the-browser-talk

(We chose one of the Python-to-JS compilers, https://skulpt.org, for the Anvil web-app platform, because it's much lighter weight than this. It's a couple of hundred kb on the wire, and you can call to the server for any heavy lifting.)

    from datetime import datetime as dt
    from utils import add_class, remove_class
    from js import console

    tasks = []

    # define the task template that will be use to render new templates to the page
    task_template = Element("task-template").select('.task', from_content=True)
    task_list = Element("list-tasks-container")
    new_task_content = Element("new-task-content")

    def add_task(*ags, **kws):
    # create task
    task_id = f"task-{len(tasks)}"
    task = {"id": task_id, "content": new_task_content.element.value, "done": False, "created_at": dt.now()}

    tasks.append(task)
    
    # add the task element to the page as new node in the list by cloning 
    taskHtml = task_template.clone(task_id, to=task_list)
    taskHtmlContent = taskHtml.select('p')
    taskHtmlContent.element.innerText = task['content']
    taskHtmlCheck = taskHtml.select('input')
    task_list.element.appendChild(taskHtml.element)
    
    def check_task(evt=None):
        task['done'] = not task['done']
        if task['done']:
        add_class(taskHtmlContent, "line-through")
        else:
        remove_class(taskHtmlContent, "line-through")

    new_task_content.clear()
    taskHtmlCheck.element.onclick = check_task

    def add_task_event(e):
    if (e.key == "Enter"):
        add_task()

If you are already using Python on the backend, not having to hire/train a completely different skill set/stack is appealing. Sure, the browser and CSS/HTML specialism is going to remain, but not having to split your team by JS vs <backend-language> would make it much easier for a team to collaborate and share work.

I think Python in the browser only has to be “almost as good” in a direct comparison for it to actually win out as the best choice organizationally for many teams.

This isn't good for most web use cases but there are some major new use cases that it enables.

Pyodide is in Python documentation all over the place, for instance on https://numpy.org/

Python has many libraries that JS is missing. Particularly the scientific computing ecosystem has a lot of very well supported Python packages but fewer JavaScript packages. They also can benefit a lot from connection to a UI.

Two key use cases for this stuff are Python education and scientific computing. Students have a hard time installing Python locally. Generally scientists want to share their results broadly, but they probably did their analysis in Python.

Here's another example of a good use case: https://www.socialfinance.org.uk/blogs/analysing-sensitive-d...

PyScript is a Pythonic alternative to Scratch, JSFiddle or other "easy to use" programming frameworks, making the web a friendly, hackable, place where anyone can author interesting and interactive applications.

https://github.com/pyscript/pyscript

But some other low hanging fruit include unvendoring the special encodings for Asian languages (hopefully everyone uses utf8), the decimal library, and the xml library which are all quite large and only occasionally used.

A public marketing page where it's the random internet of totally new/anonymous users who want to instantly find out info about your product would be the worst use case for this IMHO.

This is the actual CPython runtime with full standard library and many of the Python mathematical and plotting libraries compiled to WASM, running in the browser. It can also be included with other HTML and JavaScript on a web page just by wrapping the Python in a tag.

Asking these web devs turned desktop app developers to learn python is probably a bridge too far…