如何比较 2 arrays 并获得相互元素的数量？

Question

I have 2 arrays like:

array_A: [0 0 0 1 0 1 0 1 1 1] which is predicted and

array_B: [1 0 1 1 0 0 0 1 1 0] is the true labels, thus Array B has 2 classes, 0 and 1.

I would like to compare Array A to Array B but for only once class, let's say 0 for example where the prediction is correct. Visually it gives us 3. I tried with like with np.where(array_A==array_B],1,0) but it doesn't work. How should I do this using python?

Answer 1

You can build a list using a list comprehension over the zip of the two input lists.

Eg

a = [0, 0, 0, 1, 0, 1, 0, 1, 1, 1]
b = [1, 0, 1, 1, 0, 0, 0, 1, 1, 0]
[x for x, y in zip(a, b) if x == y == 0]

Elements from the two lists are only included in this new list if the corresponding elements in each input list are equal, and also are 0 .

The length of the list is the value you want.

len([x for x, y in zip(a, b) if x == y == 0])