python cumsum函数的具体使用

>import numpy as np
> a=[1,2,3,4,5,6,7]
> np.cumsum(a)
array([ 1,  3,  6, 10, 15, 21, 28, 36, 45, 55, 75, 105])

>import numpy as np
> c=[[1,2,3],[4,5,6],[7,8,9]]
> np.cumsum(c,axis=0)
array([[ 1, 2, 3],
    [ 5, 7, 9],
    [12, 15, 18]])
> np.cumsum(c,axis=1)
array([[ 1, 3, 6],
    [ 4, 9, 15],
    [ 7, 15, 24]])

>import numpy as np
> a
[[[1, 2, 3], [4, 5, 6]], [[7, 8, 9], [10, 20, 30]]]
> np.cumsum(a,axis=0)
array([[[ 1, 2, 3],
    [ 4, 5, 6]],
 
    [[ 8, 10, 12],
    [14, 25, 36]]])
> np.cumsum(a,axis=1)
array([[[ 1, 2, 3],
    [ 5, 7, 9]],
 
    [[ 7, 8, 9],
    [17, 28, 39]]])
> np.cumsum(a,axis=2)
array([[[ 1, 3, 6],
    [ 4, 9, 15]],
 
    [[ 7, 15, 24],
    [10, 30, 60]]])

[ //axis=0
       [//axis=1。同时是axis=0所对应的第 1 行，注意是此中括号包含的整个内容
          [1, 2, 3], //axis=2。同时是 axis=1所对的第1行
          [4, 5, 6] //axis=2
       ],
       [//axis=1。同时是axis=0所对应的第 2行
          [7, 8, 9], //axis=2。同时是 axis=1所对的第1行
          [10, 20, 30] //axis=2
       ],
   ]