Why is this so much faster?
Now, Streamlit keeps a single Python session running until you kill the server. This means that Streamlit can re-run your code without kicking off a new process; imported libraries are cached to memory. An added bonus is that st.cache now caches to memory instead of to disk.
What happens if I run Streamlit the old way?
If you run $ python your_script.py the script will execute from top to bottom, but won't produce a Streamlit app.
What are the limitations of the new architecture?
To switch Streamlit apps, first you have to kill the Streamlit server with Ctrl-c. Then, you can use streamlit run to generate the next app.
Streamlit only works when used inside Python files, not interactively from the Python REPL.
What else do I need to know?
The strings we print to the command line when liveSave is on have been cleaned up. You may need to adjust any RegEx that depends on those.
