Question

python 怎么算矩阵每列的和

例子：
mat = [ [1,2,3], [10,20,30], [100,200,300] ]
list_sums_cols = addValuesInAllCols(mat)
print (list_sums_cols)
should produce the output:[111, 222, 333]

Answer 1

output = []
nrow = len(mat)
ncol = len(mat[0])
for i in range(ncol):
    output.append(sum([mat[x][i] for x in range(nrow)]))
print output