def checkio(matr): clone = zip(*matr) modifiedClone = [] for row in clone: modifiedClone.append(list(map(mult, row))) for i, row in enumerate(matr): for j, cell in enumerate(matr[i]): if cell != modifiedClone[i][j]: return False return True def mult(e): return -1 * e if __name__ == '__main__': assert checkio([[0, 1, 2], [-1, 0, 1], [-2, -1, 0]]) == True, 'First' assert checkio([[0, 1, 2], [-1, 1, 1], [-2, -1, 0]]) == False, 'Second' assert checkio([[0, 1, 2], [-1, 0, 1], [-3, -1, 0]]) == False, 'Third' print('All ok')