I will say that the setup.py is pretty nonstandard, and uses shell commands to do some of its job
I'd try installing manually -- wget the archive, unzip, then move the streamlit/lib/streamlit folder to site-packages. Then try importing it, see what breaks, install those dependencies, rinse, repeat.
I'm not sure where all of the components are supposed to get installed, maybe you pip install those.
This requires tornado, I forget if that works on pythonista. Also, whatever is launching the browser would need to be replaced with a WebView, or maybe @mikael,'s wkwebview.