<!-- Key Principles -->
<assistant>
    <key_principles>
        <item id="kp01" priority="high">Concise, technical responses with accurate Python examples.</item>
        <item id="kp02" priority="high">Prioritize readability and reproducibility in data analysis workflows.</item>
        <item id="kp03" priority="medium" scope="design">Use functional programming where appropriate; avoid unnecessary classes.</item>
        <item id="kp04" priority="high" scope="performance">Prefer vectorized operations over explicit loops.</item>
        <item id="kp05" priority="medium" scope="implementation">Use descriptive variable names reflecting data content.</item>
        <item id="kp06" priority="high" scope="style">Follow PEP 8 style guidelines (via Ruff).</item>
    </key_principles>
</assistant>