Sorting arrays in NumPy by column

Question

How can I sort an array in NumPy by the nth column?

For example,

a = array([[9, 2, 3],
           [4, 5, 6],
           [7, 0, 5]])

Answer 1

I suppose this works: a[a[:,1].argsort()]

This indicates the second column of a and sort it based on it accordingly.