如何在pandas中每隔n行重复2列？

import pandas as pd

data = {'A': [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
        'B': [11, 12, 13, 14, 15, 16, 17, 18, 19, 20],
        'C': [21, 22, 23, 24, 25, 26, 27, 28, 29, 30]}
df = pd.DataFrame(data)

n = 2
repeated_df = df.iloc[::n].reset_index(drop=True).reindex(df.index).ffill()

print(repeated_df)

    A   B   C
0   1  11  21
1   1  11  21
2   3  13  23
3   3  13  23
4   5  15  25
5   5  15  25
6   7  17  27
7   7  17  27
8   9  19  29
9   9  19  29
10 10  20  30