这是使用样品运行-

In [976]: arr
Out[976]: array([55, 52, 13, 64, 25, 76, 47, 18, 69, 88])

In [977]: start_index
Out[977]: array([2, 3, 4])

In [978]: L = 5

In [979]: out
Out[979]: 
array([[13, 64, 25, 76, 47],
       [64, 25, 76, 47, 18],
       [25, 76, 47, 18, 69]])