使用Pandas数据框计算加权平均值

您可以使用以下方法 在组内 获得 归一化的权重

transform

>>> df['weight'] = df['dist'] / df.groupby('ind')['dist'].transform('sum')>>> df['weight']0    0.3571431    0.4166672    0.2500003    0.2857144    0.5833335    0.2857146    0.7142867    0.107143Name: weight, dtype: float64

然后，您只需要将这些权重乘以值，然后求和：

>>> df['wcas'], df['wdiff'] = (df[n] * df['weight'] for n in ('cas', 'diff'))>>> df.groupby('ind')[['wcas', 'wdiff']].sum()         wcas     wdiffind         g    6.714286  2.785714la   3.107143  4.882143p    3.750000  2.558333

编辑：就地突变：

>>> backup = df.copy()     # make a backup copy to mutate in place>>> cols = df.columns[:2]  # cas, diff>>> df[cols] = df['weight'].values[:, None] * df[cols]>>> df.groupby('ind')[cols].sum()          cas      diffind         g    6.714286  2.785714la   3.107143  4.882143p    3.750000  2.558333