數據變成按照行變成一維輸出（數據變成按照列變成一維輸出）

array([[ 0,  1,  2],
       [ 3,  4,  5],
       [ 6,  7,  8],
       [ 9, 10, 11]])
       ##按照行讀取
for i in a:
    print(i)
##數據變成按照行變成一維輸出
for i in a.ravel():
    print(i)
##數據變成按照列變成一維輸出
for i in a.ravel("F"):
    print(i)

[0 1 2]
[3 4 5]
[6 7 8]
[ 9 10 11]
0
1
2
3
4
5
6
7
8
9
10
11
0
3
6
9
1
4
7
10
2
5
8
11