--description--

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

More resources:

• <a href="https://github.com/ine-rmotr-curriculum/data-cleaning-rmotr-freecodecamp" target="_blank" rel="noopener noreferrer nofollow">Notebooks on GitHub</a>
• <a href="https://colab.research.google.com/github/googlecolab/colabtools/blob/master/notebooks/colab-github-demo.ipynb" target="_blank" rel="noopener noreferrer nofollow">How to open Notebooks from GitHub using Google Colab.</a>

--questions--

--text--

What will the following code print out?

import pandas as pd
import numpy as np

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

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

--answers--

3

--video-solution--

1