organizing-streamlit-code

To organize Streamlit code, structure projects with dedicated modules by placing UI components in an app_pages directory and business logic in a utils directory. This modularization keeps the main entry point concise and ensures UI code remains separate from data processing.

The best way to structure a multi-page Streamlit app is using a defined directory layout with a streamlit_app.py entry point, an app_pages folder for navigation, and a utils folder for reusable components to prevent spaghetti code as the app scales.

You need to modularize your Streamlit app when it expands beyond a single file and faces maintainability issues. Separating UI rendering and data processing into dedicated modules becomes necessary to manage navigation, reuse components, and scale effectively.

Yes, you can test business logic by isolating it in utility modules within the utils directory. This separation ensures data processing has no UI dependencies, enabling easier testing and reuse of business logic without rendering Streamlit components.

Streamlit apps become hard to maintain when UI and business logic mix in a single file, creating spaghetti code. Without a modular structure separating UI components and logic into dedicated pages and utilities, scaling and reuse become difficult.