freeCodeCamp/curriculum/challenges/english/08-data-analysis-with-python/data-analysis-with-python-course/data-cleaning-introduction.english.md

id, title, challengeType, isHidden, videoId

id	title	challengeType	isHidden	videoId
5e9a093a74c4063ca6f7c15d	Data Cleaning Introduction	11	false	ovYNhnltVxY

Description

Instead of using notebooks.ai like it shows in the video, you can use Google Colab instead.

More resources:

• Notebooks on GitHub
• How to open Notebooks from GitHub using Google Colab.

Tests

question:
  text: |
    What will the following code print out?

    ```py
    import pandas as pd
    import numpy as np

    s = pd.Series(['a', 3, np.nan, 1, np.nan])

    print(s.notnull().sum())
    ```

  answers:
    - |
      3
    - |
      ```
      0     True
      1     True
      2    False
      3     True
      4    False
      dtype: bool
      ```
    - |
      ```
      0    False
      1    False
      2     True
      3    False
      4     True
      dtype: bool
      ```
  solution: 1