Python的列表还可以嵌套，以下用三种方法来说明
1 方法一
>>> matrix =[[1,2,3,4],[5,6,7,8],[9,10,11,12]]>>> transposed =[]>>>for i in range(4):transposed_row =[]for row in matrix:transposed_row.append(row[i])transposed.append(transposed_row)>>> transposed[[1,5,9],[2,6,10],[3,7,11],[4,8,12]]
2 方法二
>>> transposed =[]>>>for i in range(4):transposed.append([row[i]for row in matrix])>>> transposed[[1,5,9],[2,6,10],[3,7,11],[4,8,12]]
3 方法三
>>>[[row[i]for row in matrix]for i in range(4)][[1,5,9],[2,6,10],[3,7,11],[4,8,12]]
