รอบต่ำสุดสำหรับแนวรุกเมื่อผลรวมน้อยกว่า 150 คือเท่าไร?
What is the lowest round for an offensive guard when the overall is smaller than 150?
df = pd.DataFrame(columns=['round', 'overall', 'position'])
df[(df['overall']<150) & (df['position']=='offensive guard')]['round'].min()