我想创建一个新的相对分数（列），将f1车手与给定年份和给定车队内的队友进行比较。
我的数据如下所示：

stats_df.head()

>       driver  year    team    points
>     0 AIT 2020    Williams    0.0
>     1 ALB 2019    Red Bull    76.0
>     2 ALB 2019    AlphaTauri  16.0
>     3 ALB 2020    Red Bull    105.0
>     4 ALO 2013    Ferrari     242.0

我累了：

teams = stats_df['team'].unique()
years = stats_df['year'].unique()
drivers = stats_df['driver'].unique()

for year in years:
    for team in teams:
        team_points = stats_df['points'].loc[stats_df['team']==team].loc[stats_df['year']==year].sum()
        for driver in drivers:
            driver_points = stats_df['points'].loc[stats_df['team']==team].loc[stats_df['year']==year].loc[stats_df['driver']==driver]
            power_score = driver_points/(team_points/2)
            stats_df['power_score'].loc[stats_df['team']==team].loc[stats_df['year']==year].loc[stats_df['driver']==driver] = power_score

导致新列中出现NaN（'power_score'）。
我们将不胜感激。