matrix rotation.py

# -*- coding: utf-8 -*-
# <nbformat>3.0</nbformat>

# <codecell>

matrix=[[1,2,3,4,5],
        [6,7,8,9,10],
        [11,12,13,14,15],
        [16,17,18,19,20],
        [21,22,23,24,25]
        ]

matrix_clockwise=[
        [21, 16, 11, 6, 1], 
        [22, 17, 12, 7, 2],
        [23, 18, 13, 8, 3],
        [24, 19, 14, 9, 4],
        [25, 20, 15, 10, 5]
        ]

matrix_anti_clockwise = [
        [5, 10, 15, 20, 25], 
        [4, 9, 14, 19, 24], 
        [3, 8, 13, 18, 23], 
        [2, 7, 12, 17, 22], 
        [1, 6, 11, 16, 21]
        ]

# <codecell>

rotate_clockwise = lambda matrix: [[matrix[row][column] for row in reversed(range(len(matrix)))] for column in range(len(matrix[0]))]
rotate_anti_clockwise = lambda matrix: [[matrix[row][column] for row in range(len(matrix))] for column in reversed(range(len(matrix[0])))]

# <codecell>

assert rotate_clockwise(matrix) == matrix_clockwise
assert rotate_anti_clockwise(matrix) == matrix_anti_clockwise