Streamlit code organization

For most simple apps, keep everything in one file—it's cleaner and more straightforward. The app file should read like a normal Python script for data processing, with a few Streamlit commands sprinkled in.

Name the main file streamlit_app.py (Streamlit's default).

When to split

Keep in one file (most apps):

• Apps under ~1000 lines
• One-off scripts and prototypes
• Apps where logic is straightforward

Consider splitting when:

• Data processing is complex (50+ lines of non-UI code)
• Multiple pages share logic
• You want to test business logic separately

If splitting makes sense, here's how to organize it.