Zero Border Around a Matrix

easynumpy_manipulation

Implement pad_border(X).

Given a 2D array X of shape (m, n), return a (m + 2, n + 2) array that is X surrounded by a one-cell border of zeros. Build it yourself with slicing — np.pad is not allowed — and no for/while loops.

Constraints

no scipy, sklearn
no pad
no for/while loops

Your solution

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Hints

Hint 1

Allocate a zeros array two larger in each dimension, then drop X into the middle with slicing.