用GroupBy实现熊猫数据帧上的自定义移动平均

import pandas as pd

df = pd.DataFrame({'日期': ['2022-01-01', '2022-01-02', '2022-01-03', '2022-01-04', '2022-01-05', '2022-01-06'],
                   '数值': [1, 2, 3, 4, 5, 6]})

df['日期'] = pd.to_datetime(df['日期'])

def moving_average(x):
    return x.rolling(window=3, min_periods=1).mean()

df['移动平均'] = df.groupby(['日期'])['数值'].apply(moving_average)

print(df)

          日期  数值     移动平均
0 2022-01-01   1  1.000000
1 2022-01-02   2  1.500000
2 2022-01-03   3  2.000000
3 2022-01-04   4  3.000000
4 2022-01-05   5  4.000000
5 2022-01-06   6  5.000000