python numpy-执行向量和矩阵加法的函数

Question

I'm working on the problem which asks me:

Add two NumPy vectors or matrices together, if possible. If it is not possible to add the two vectors/matrices together (because their sizes differ), return False.

Here is my approach:

import numpy as np

def mat_addition(A, B):
    if A.shape != B.shape:
        return False
    else:
        return np.sum(A,B)

But when I run the code for testing, it says

TypeError: only integer scalar arrays can be converted to a scalar index

Can someone tell me what's wrong with my code?

Answer 1

np.sum can in fact be used in the way you want. You just need to wrap the arguments you pass to np.sum in a list:

import numpy as np

def mat_addition(A, B):
    if A.shape != B.shape:
        return False
    else:
        return np.sum([A,B])

a = np.arange(5*3).reshape(5,3)
b = np.arange(5*3, 5*3*2).reshape(5,3)
print(mat_addition(a,b))

Output:

435

As per the numpy.sum docs, this function expects a single "array_like" object as its first argument. A list of arrays is a perfectly valid "array_like" object, so the above code works.