freeCodeCamp/curriculum/challenges/chinese/08-data-analysis-with-python/numpy/accessing-and-changing-elements,-rows,-columns.md

id, title, challengeType, isHidden, videoId

id	title	challengeType	isHidden	videoId
5e9a0a8e09c5df3cc3600ed4	Accessing and Changing Elements, Rows, Columns	11	false	v-7Y7koJ_N0

Description

Tests

question:
  text: |
    What code would change the values in the 3rd column of both of the following Numpy arrays to 20?

    ```py
    a = np.array([[1, 2, 3, 4, 5], [6, 7, 8, 9, 10]])

    # Output:
    # [[ 1  2  20  4  5]
    # [ 6  7 20  9 10]]
    ```
  answers:
    - |
      ```python
      a[:, 3] = 20
      ```
    - |
      ```python
      a[2, :] = 20
      ```
    - |
      ```python
      a[:, 2] = 20
      ```
    - |
      ```python
      a[1, 2] = 20
      ```
  solution: 3