np.sort(students, order='height') np.array(students_details, dtype=data_type) 'name', 'S15' 'class', int 'height', float 'James', 5, 48.5 'Nail', 6, 52.5 'Paul', 5, 42.10 'Pit', 5, 40.11 data_type students_details Original array b'James', 5, 48.5 b'Nail', 6, 52.5 b'Paul', 5, 42.1 b'Pit', 5, 40.11 Sort by height b'Pit', 5, 40.11 b'Paul', 5, 42.1 b'James', 5, 48.5 b'Nail', 6, 52.5