a = np.array([[3, 2], [6, 2], [3, 6], [3, 4], [5, 3]])
atmp = np.sort_complex(a[:, (0)] + a[:, (1)] * 1j)
b = np.array([[np.real(x), np.imag(x)] for x in atmp])
b
Sorting a 2D numpy array by multiple axes