Looping through multidimensional array

[saraeauwhy]

Hi, I'm trying to loop through two lists.
I want to compare the arrays in the list 'center' to the arrays in the larger list 'mail_vecs'.When the array is the same I want to return the index of the array in mail_vecs that is the same as the array in 'center'.
The shape of 'center'is (15, 100)
The shape of 'mail_vecs' is (271304, 100)

I'm not sure how to do this as I'm rather new to using python. I tried something but I know it is not good. Thanks in advance!

index_center = []
for vec2 in np.nditer(center):
    for index, vec1 in enumerate(np.nditer(mail_vecs)):
        if np.array_equal(vec1, vec2):
            index_center.append(index)
print(np.shape(index_center))