如何基于滚动窗口查找将列追加到Panda dataframe？

import pandas as pd

data = {'A': [1, 2, 3, 4, 5],
        'B': [6, 7, 8, 9, 10]}
df = pd.DataFrame(data)

window_size = 3
rolling_window = df['A'].rolling(window=window_size)

df['Rolling Mean'] = rolling_window.mean()

import pandas as pd

data = {'A': [1, 2, 3, 4, 5],
        'B': [6, 7, 8, 9, 10]}
df = pd.DataFrame(data)

window_size = 3
rolling_window = df['A'].rolling(window=window_size)
df['Rolling Mean'] = rolling_window.mean()

print(df)

   A   B  Rolling Mean
0  1   6           NaN
1  2   7           NaN
2  3   8      2.000000
3  4   9      3.000000
4  5  10      4.000000