matrice = [ [1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12], ] print(matrice) ''' [ [1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]] ''' transpose = [] for element in range(len(matrice[0])): temp = [] for ligne in matrice: temp.append(ligne[element]) transpose.append(temp) print(transpose) ''' [[1, 5, 9], [2, 6, 10], [3, 7, 11], [4, 8, 12]] '''