Python 2行或更多行pandas中累积值的唯一计数

df
###
   hf0  hf1  hf2  hf3  hf4  hf5 sample
0    7    4    2    2    7    2    7yr
1    8    5    5    6    5    6    7yr
2    9    6    8   10    7   10    7yr
3   10    7   11   14    5   14    7yr
4   11    8   14   18    7   18    7yr

滚动窗口rolling=2

rolling = 2

ar = df.loc[:,'hf0':'hf5'].values
length = ar.shape[1]
head_arrs = np.zeros((rolling-1, rolling*length))
cubic = np.lib.stride_tricks.sliding_window_view(ar, (rolling,length)).astype(float)
plane = cubic.reshape(-1,rolling*length)

for i in range(rolling-1,0,-1):
        head_arr_l = plane[0,:i*length]
        head_arr_l = np.pad(head_arr_l.astype(float), (0,length*(rolling-i)), 'constant', constant_values=np.nan)
        head_arr_l = np.roll(head_arr_l, length*(rolling-i))
        head_arrs[i-1,:] = head_arr_l

plane = np.insert(plane, 0, head_arrs, axis=0)
df['rolling_nunique'] = pd.DataFrame(plane).nunique(axis=1)
df
###
   hf0  hf1  hf2  hf3  hf4  hf5 sample  rolling_nunique
0    7    4    2    2    7    2    7yr                3
1    8    5    5    6    5    6    7yr                6
2    9    6    8   10    7   10    7yr                6
3   10    7   11   14    5   14    7yr                8
4   11    8   14   18    7   18    7yr                7

滚动窗口rolling=3

   hf0  hf1  hf2  hf3  hf4  hf5 sample  rolling_nunique
0    7    4    2    2    7    2    7yr                3
1    8    5    5    6    5    6    7yr                6
2    9    6    8   10    7   10    7yr                8
3   10    7   11   14    5   14    7yr                8
4   11    8   14   18    7   18    7yr                9

If the rolling window covers whole rows of df,
in this case, df.shape[0] = 5,
Rolling window rolling=5

   hf0  hf1  hf2  hf3  hf4  hf5 sample  rolling_nunique
0    7    4    2    2    7    2    7yr                3
1    8    5    5    6    5    6    7yr                6
2    9    6    8   10    7   10    7yr                8
3   10    7   11   14    5   14    7yr               10
4   11    8   14   18    7   18    7yr               11