--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.

--question--

--text--

What will the following code print out?

import pandas as pd
import numpy as np

s = pd.Series([np.nan, 1, 2, np.nan, 3])
s = s.fillna(method='ffill')

print(s)

--answers--

0    1.0
1    1.0
2    2.0
3    3.0
4    3.0
dtype: float64

---

0    NaN
1    1.0
2    2.0
3    2.0
4    3.0
dtype: float64

---

0    NaN
1    1.0
2    2.0
3    NaN
4    3.0
dtype: float64

--video-solution--

2