Usually we've been prototyping with streamlit, but found that at times to be clunky. FastUI still has rough edges, but we made it work for our lightweight app. Note: we generally found it snappier than streamlit.
That said, I’ve found it to be clunky in a few ways:
1. State management is not intuitive — anything that involves rendering complex state/reacting at it changes requires a ton of session state type stuff.
2. I’ve very often had to go into css/markdown hacks
3. The control flow of when it’s running/executing makes for clunky interactions
4. Some API decisions are painful. For instance, a block str comment in the file will render as st.write
5. Long running (or even not instant tasks) make for some annoying engineering challenges — the UI is tied to the compute, so you have to be smart about juggling it
6. Caching is not smart — it’s quite useful, but it’s easy to get lost in caching/state
I’ve been dreaming about streamlit but a little more state/function oriented. E.g. react-based. Not far from fastUI
These are both great tools for prototyping, but I’ve found that I’ll pull up tailwind + some UI framework when I want something slick and it’ll take a few times as long.
If you decide to give it a try and have trouble, please email me (email in profile) or drop by the Discord (https://discord.gg/yMGCamUMnS).
The Python version is a port from its R stablemate (well, maybe more than a port: a re-engineering). If it's as solid as its R parent then it'll be a very useful addition to the Python UI landscape.