sum() 没有axis参数表示全部数据相加
axis=0,表示按列相加
axis=1,表示按行相加
a = array([[1,2,3],[4,5,6]])
print(a)
b = sum(a)
print (b)
c = sum(a, axis=0)
print(c)
d = sum(a, axis=1)
print(d)
output:
a:
[[1 2 3]
[4 5 6]]
b:
21
c:
[5 7 9]
d:
[ 6 15]
a = array([1,2,3])
print(a)
b = sum(a)
print (b)
c = sum(a, axis=0)
print(c)
output:
a:
[1 2 3]
b:
6
c:
6