# 867. Transpose Matrix

#### Easy

***

Given a 2D integer array `matrix`, return *the **transpose** of* `matrix`.

The **transpose** of a matrix is the matrix flipped over its main diagonal, switching the matrix's row and column indices.

![](https://assets.leetcode.com/uploads/2021/02/10/hint_transpose.png)

 

**Example 1:**

```
Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]
Output: [[1,4,7],[2,5,8],[3,6,9]]
```

**Example 2:**

```
Input: matrix = [[1,2,3],[4,5,6]]
Output: [[1,4],[2,5],[3,6]]
```

 

**Constraints:**

* `m == matrix.length`
* `n == matrix[i].length`
* `1 <= m, n <= 1000`
* `1 <= m * n <= 105`
* `-109 <= matrix[i][j] <= 109`

```python
class Solution:
    def transpose(self, matrix: List[List[int]]) -> List[List[int]]:
        m = [[0]*len(matrix) for _ in range(len(matrix[0]))]
        for i in range(len(matrix)):
            for j in range(len(matrix[0])):
                m[j][i] = matrix[i][j]
        return m
```