Streamlit Development Skills

1. Architecture Pattern

• •Logic Separation: Keep app.py for View/Controller logic only.
  • •Move complex calculations to uci/.
  • •Move helper UI functions (plots, formatting) to utils/visuals/.
• •Monolith: app.py is the single entry point. Do not create multi-page apps unless architecture changes.

2. Performance & Caching

• •Data: Use @st.cache_data for loading CSVs and heavy dataframes.
  python

  @st.cache_data
  def load_data(path: Path) -> pd.DataFrame:
      return pd.read_csv(path)
  

• •Resources: Use @st.cache_resource for loading ML models or DB connections.

3. Session State Management

• •Persistence: Use st.session_state to store simulation results between re-runs.
• •Initialization: Always check if key exists before access.
  python

  if 'simulation_results' not in st.session_state:
      st.session_state.simulation_results = None
  

4. User Experience (UI/UX)

• •Language: All visible text (titles, buttons, warnings) must be in Spanish.
• •Variables: Load text from utils/constants/messages.py.
• •Feedback:
  • •Use st.spinner() for running simulations.
  • •Use st.progress() for batch experiments.
  • •Use st.error/warning/info for status updates.

5. Visualizations

• •Library: plotly (interactive) or matplotlib/seaborn (static).
• •Theme: Respect user theme preference (Light/Dark) where possible, or stick to project defaults defined in utils/constants/theme.py.