python嵌套列表展示

Python的列表还可以嵌套，以下用三种方法来说明

1 方法一

1. >>> matrix =[[1,2,3,4],[5,6,7,8],[9,10,11,12]]
2. >>> transposed =[]
3. >>>for i in range(4):
4. transposed_row =[]
5. for row in matrix:
6. transposed_row.append(row[i])
7. transposed.append(transposed_row)
10. >>> transposed
11. [[1,5,9],[2,6,10],[3,7,11],[4,8,12]]

2 方法二

1. >>> transposed =[]
2. >>>for i in range(4):
3. transposed.append([row[i]for row in matrix])
6. >>> transposed
7. [[1,5,9],[2,6,10],[3,7,11],[4,8,12]]

3 方法三

1. >>>[[row[i]for row in matrix]for i in range(4)]
2. [[1,5,9],[2,6,10],[3,7,11],[4,8,12]]