Nick Heidfeld ขับบนกริดที่ใหญ่กว่า 4 กี่รอบ
How many laps did Nick Heidfeld drive on grids larger than 4?
df = pd.DataFrame(columns=['laps', 'grid', 'driver'])
df[(df['grid'].astype(int) > 4) & (df['driver'] == 'nick heidfeld')].laps.sum()