using-streamlit-session-state

To persist data across Streamlit reruns, use `st.session_state` to store and retrieve variables. This manages application state, ensuring user interactions and widget values remain intact throughout the execution cycle.

Synchronizing widget values with session state in Streamlit involves linking widgets directly to `st.session_state` keys. This automatically updates and persists user interactions without requiring manual value extraction during reruns.

Handle callbacks for user actions in Streamlit by assigning functions to widget `on_change` parameters. These callbacks execute immediately, updating `st.session_state` before the main script reruns to reflect new state.

Your Streamlit app loses user selections because variables reset on each rerun. Initializing variables in `st.session_state` ensures data persistence, allowing selections on one page to be remembered on subsequent pages.

Yes, understanding Streamlit's execution model is required for effective session management. Knowing how the script reruns top-to-bottom after interactions allows you to correctly initialize and update `st.session_state` variables.

A limitation of using session state for data persistence in Streamlit is that data is scoped only to the current user session. It does not share state across different users or permanently store data outside the active browser session.