เมื่อ Thomas Clayton มีกำไรน้อยกว่า 71 ค่า long สูงสุดคือเท่าใด
When Thomas Clayton had a gain less than 71, what was the highest long value?
df = pd.DataFrame(columns=['long', 'name', 'gain'])
df[(df['name'] == 'Thomas Clayton') & (df['gain'] < '71')]['long'].max()