Show HN: Full Python GUI apps in the browser – no JavaScript, no server
github.comI have been working on Dear ImGui Bundle since 2022, but it is the first time I talk about it here. It is a framework around Dear ImGui for building interactive applications in Python and C++. It comes with batteries included: Plotting, image inspection, Markdown, node editors, 3D gizmos, knobs, toggles, etc.
https://imgui-bundle.pages.dev
It now also runs smoothly in the browser via pyodide: The playground below is a python app running in your browser (no server, no JavaScript). You can edit the code on the left and click Run. It even works on mobile.
https://imgui-bundle.pages.dev/playground
I have a strong interest in providing tools that help others express their creativity. This project aims to be a step in this direction as it helps develop GUIs where the code is extremely readable & hackable.
Some of the goals it addresses:
- Bring true Immediate Mode GUI to Python and C++
- A versatile range of high quality libraries: Widgets, Plots, Image Analysis, Node edition, markdown rendering
- Multiplatform apps in C++: works on all platform in C++ (desktop, mobile, emscripten)
- Deploy python apps to the web
- High quality python bindings that are always up-to-date (because they are auto-generated)
- Smooth transition between C++ and Python (same APIs for both)
I'd be happy to answer questions!
This is really neat, and I think I can use it in some of my projects as a simple front end to physical simulation tools. One question I have: do you have true 3D bindings? I see there is ImPlot3D, but right now I need to render meshes in OpenGL (or WebGL as the case will be). Is there a way for me to define shaders and feed it triangle soup?
Thanks!
Yes I do have access to webgl. I added some examples to explain this:
For example look at:
https://imgui-bundle.pages.dev/playground/?demo=webgl_textur...
There are two more examples: look at the WebGL examples in the combo-box at the top-right of the page.
Enjoy! If you end up using it, please try to keep me informed :-)
Is this downloading and installing Python packages into the browser via wasm?
I like the idea a little bit. Mostly because I don't like javascript. So I say keep going for it, it could fill some niches.
I'm sure you know this, but the page takes like 30s to load on mobile. It wasn't a comfortable ux. Once it did load it seemed pretty fast though so kudos. Kind of gave me macromedia flash vibes from 2002.
Thanks! I don't like javascript either, and I certainly dislike CSS :-)
Yes, the initial download of pyodide is about 5 MB. After that it is another 5MB for the bundle wheel.
But there is some hope: Based on test I just did, I see I did not setup headers so that the wheel and pyodide are cached in a browser (or in its fs): this could reduce reload times by a sizable factor.
Once loaded you can run at 60 FPS (or even 120 FPS depending on the browser's vsync).
As you can see in the playground: you can then switch from app to app instantly once pyodide is loaded and running. It almost feels like going from a page to another. You can see that when using the combobox to select example at the top right in the playground.
If no JavaScript then what enables interactivity?
Web assembly? This started out as a bowdlerised form of JavaScript (asm.js) but evolved to become is own thing.
You still need JavaScript to instantiate WebAssembly and let it interact with the page, which is why your sibling comment admits there's still a bit of JS.
Thanks for the question! I should have said almost no JavaScript:
There is a minimal amount of JavaScript just to download and run pyodide and then it is only Python: see example at
https://imgui-bundle.pages.dev/playground/?demo=p_35_minimal...
Very very impressive! So many use cases for this. Thanks again
I agree with the other comments. Its super cool after it eventually loads.
For real world use I don't think its practical if its only goal is basic browser UX in Python versus JavaScript, but I can see amazing value in this for larger applications written in Python that need to make use of a Python GUI.
Absolutely. This shines when you actually want to display complex / animated / streaming data in larger applications; or if you want to create educative or training material on several pages (i.e apps here).
As an example, I once built an online stock/ticker app with it: smooth real-time updates in a nice plot. It would have been more complex with DOM based widgets (and probably less fun).
just curious -- do yall dislike JS as developers, or as users? i agree this is really cool though
This is a genuine question, and I will be honest: I do not really dislike JS. I even worked on large typescript projects and appreciated it.
What I do not like is the strange mix of technologies you have to cope with in order to work with Python on the web: your project is often a mix of python / html / css / react / js / node.
Many very nice frameworks try to abstract this and present you only the python side; but they rely on this stack internally. Once you want to reach complex use cases (such as a refresh at reasonable rate), you will have to "open the engine" and enter into this mix.
I dislike JS as a developer.... but I also dislike python, so...
Cool! Now someone should do something like this for Java!
Yes, back to 1999!