What's the simplest way to extend a numpy array in 2 dimensions?

Question

I have a 2d array that looks like this:

XX
xx

What\'s the most efficient way to add an extra row and column:

xxy
xxy
yyy


        

Answer 1

Another elegant solution to the first question may be the insert command:

p = np.array([[1,2],[3,4]])
p = np.insert(p, 2, values=0, axis=1) # insert values before column 2

Leads to:

array([[1, 2, 0],
       [3, 4, 0]])

insert may be slower than append but allows you to fill the whole row/column with one value easily.

As for the second question, delete has been suggested before:

p = np.delete(p, 2, axis=1)

Which restores the original array again:

array([[1, 2],
       [3, 4]])