一.sum函数
1.基本使用
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
from numpy import * a = array([[1, 2, 3], [4, 5, 6]]) print(a,\'\n\') b = sum(a) print(b,\'\n\') c = sum(a, axis=0) print(c,\'\n\') d = sum(a, axis=1) print(d,\'\n\') #运行结果 \'\'\' [[1 2 3] [4 5 6]] 21 [5 7 9] [ 6 15] \'\'\'
2.相关注意事项
对于一维数组，只有axis=0，表示按行相加，没有axis=1，输入axis=1会报错。
from numpy import * a = array([1, 2, 3]) # print(a,\'\n\') #[1 2 3] # # b = sum(a) # print(b,\'\n\') #6 # # c = sum(a, axis=0) # print(c,\'\n\') #6 #以下情况会报错 d = sum(a,axis=1) #numpy.core._internal.AxisError: axis 1 is out of bounds for array of dimension 1