Streamlit Core Knowledge Installation & Run Core Concepts App Execution Model Streamlit re-runs the entire script top-to-bottom on every user interaction. Use caching and session state to avoid redundant work. Session State Caching Layout & Components Columns Tabs Sidebar Expander Input Widgets Data Display Forms (batch input — single rerun on submit) Progress & Status Multipage Apps Configuration Secrets Deployment (Docker) Testing Streamlit Apps Anti-Patterns | Anti-Pattern | Fix | |--------------|-----| | Heavy I/O on every rerun | | | Global mutable state | | | Business logic in UI script…