Needing to edit .txt files before reading - is Streamlit a bad tool for this?

I’m writing a tool for a mechanical engineer. I was using Dear PyGUI but found the file dialogue a nightmare, so wondered if Streamlit would be a good choice, especially since the engineer wouldn’t have to download any Python packages to use it. He wants to upload .txt files created from finite element analysis software and be able to both have them formatted as well as see data visualisations on the information contained.

I need to be able to add delimiters and labels. This is usually a walk in the park when done locally on the file system as you just use open(), but I can’t figure out in Streamlit how to upload the txt file, alter it, then allow the engineer to download it, formatted, for use elsewhere. Apart from him being able to use the formatting, I need the delimiters in place to make the data easier for the program to parse. I think I could do that for myself by formatting the contents of the txt file as a string in Streamlit and doing the data visualisations, but I don’t know if there is a way to make the formatted data available for download again.

It’s tricky because I think I’d need to somehow store a blank .txt file in the cloud that I could write to for downloading. Permissions wouldn’t allow writing to a local file system for safety reasons, I’d imagine. Is there a way of doing this that isn’t needlessly complicated, or should I ditch Streamlit as the wrong tool for this job and keep trying to find a suitable GUI?

Ha, answered my own question. Because it is linked to GitHub, I can indeed store a blank .txt file there, then download it too. Just got it working.
Silly me!